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ENTAIL.

seeds of E. Pursætha, an East Indian species, are saponaceous, and are used for washing the hair. The plant attains a great size: its pods are sometimes fully five feet long, and six inches broad; the seeds are beautiful brown beans, so large that in Ceylon they are often hollowed out and used as tinder-boxes.

ENTAIL, or ENTAY'LE (Fr. tailler, to cut), often used by old English authors for any architectural ornament which is sculptured or cut in stone. Chaucer speaks of

'An image of an other entaile;' and other examples are given by Parker (Glossary of Architecture).

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the civil law to form a basis for the codes of modern
Europe, did not, in its original form, recognise the
right of a holder of land to alienate his feudal
benefice. But the right of the eldest son to represent
his father, both in the duties and privileges of the
fief, if not an original principle of the system, was
universally recognised in the days of its greatest
power. We shall presently see how this principle
We

was embodied in a Scottish deed of entail.
in modern nations.
come now to consider entails as they have existed

In England, the Saxons, it is said, prohibited the alienation of lands by those who had succeeded to them under condition that they should not alienate.--Wilkins's Leges Saxonice, p. 43 (note). Among the Saxons, the law of primogeniture was ENTAIL, or, as it is frequently called in Scot- not recognised. But on the establishment of the land, tailzie, from Fr. tailler, to cut, properly feudal laws in England, a practice began to prevail signifies any destination by which the legal course whereby an estate was settled upon a particular of succession is cut off, one or more of the heirs- series of heirs, as to a man and the heirs of his at-law being excluded or postponed, and the settle-body.' This is the first germ of an entail in ment of land made upon a particular heir or series England. It was called a fee-simple conditional, of heirs. The desire to preserve in our own family because the judges refused to recognise an absolute land which we have either inherited or acquired, limitation of the estate to a particular line of heirs, appears to be inherent in the human mind. The but held the destination to be conditional on the first distinct trace of the existence of entails, is birth of an heir, and that that condition having been to be found in the Roman law. The Greeks, purified, the donee was free to alienate the estate. indeed, permitted persons to name successors to The common law thus refusing to recognise entails, their estates, and to appoint a substitute who a statute was passed which had the effect of introshould take the estate on the failure of him first ducing that practice into England. This was the named. The substitute, as appointed, was per- famous statute De Donis (q. v.), whereby it was mitted to succeed on the death of the institute declared that the estate should be held secundum (as he was called) without leaving issue or without formam doni. In order to the creation of an entail alienating the estate. But this limited right fell under this statute, it was not enough that the far short of the power of entailing which has since estate was limited to a man and his heirs,' as those prevailed in various countries. At Rome, under words were held to constitute an estate in fee; it the later emperors, the practice of settling land was necessary that the estate should be given to upon a series of heirs, by means of Fideicommissa a man and the heirs of his body,' or 'to a man and (q. v.), grew up, and was sanctioned by the state. the heirs of his body by his wife Joan.' The former These deeds, which were originally simply a trust was called a general, the latter a special entail. reposed in the honour of a friend, to whom the Another form whereby lands might be entailed property was conveyed, to carry out the will of the under the statute De Donis, was by settlement in grantor, by degrees received the sanction of the Frankmarriage (q. v.). For nearly 200 years after law. In their early form, they contained merely a the passing of this act, lands settled in the form substitution of heirs. Thus, Rogo ne testamentum which it prescribed continued to be held under the faciat, donec liberos susceperit.' Rogo ut testamento fetters of a strict entail. But the tendency of the suo Seium hæredem faciat.' 'Rogo hæredem, ne hare- law, which in Scotland, as we shall presently see, ditatem alienet, sed relinquat familia.'-Heineccius, was to strengthen the power of entails, was, in s. 658. But by the later law, a much fuller form England, in the opposite direction. For a long of settlement was admitted, whereby the estate time, tenants in tail, taking advantage of legal was protected from every sort of alienation. Volo technicalities, were able practically to defeat the meas ædes non vendi ab hæredibus meis, neque limitation in tail by means of a Discontinuance. fæænerari super eas: sed manere eas firmas, sim- But it was not till the time of Edward IV. that an plices, filiis meis et nepotibus in universum tempus. effectual means of evading the provisions of the Si aliquis autem eorum voluerit vendere partem act was brought into use; this was achieved by suam, vel funerari super eam, potestatem habeat means of a process called a common recovery. See vendere coheredi suo et fœnerari ab eo: si autem FINES AND RECOVERIES. By this process, a tenant aliquis præter haec fecerit, erit quod obligatur, inutile in tail could bar the entail, and convert the estate atque irritum.'-Dig. xxxi. 88, s. 15. Here we into a fee-simple. Another mode of barring at entail have an example of the principal clauses of a was by means of a Fine (q. v.). It had been declared strict entail as subsequently more fully carried by the statute De Donis, that levying a fine of lands out in Scotland. It is impossible to doubt that should be no bar to the entail; but by 32 Hen. this Roman form must have been adopted by the VIII. c. 36, it was enacted that a fine of lands, Scottish lawyers in framing their deeds of entail. when duly levied, should be a complete bar to the The limitation to a particular line of descent, the tenant in tail, and those claiming under him. It is prohibition to alienate or burden with debt, and the to be observed that the operation of a fine was still more peculiar feature of the declaration of confined to those claiming under the tenant in tail; forfeiture in case of non-compliance, are to be found those who had rights of reversion or remainder in both forms. There are, however, two points in under the grantor of the entail were not excluded by which the Roman law differed from that which this species of assurance; so that by means of a prevailed for many years in Scotland-viz., that the recovery only could an estate tail be converted into former did not recognise the right of primogeniture, a fee-simple. From the introduction of common and that the limitation of the deed was restricted to recoveries till the passing of the Fines and Recoveries four generations. For the right of primogeniture, as Act (3 and 4 Will. IV. c. 74), a period of more than recognised in deeds of entail, we are indebted to the 300 years, it was impossible that an estate could be feudal law. That system, which has united with held under the fetters of an entail, if the tenant

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ENTASIS-ENTELLUS MONKEY.

in tail and the next heir chose to combine to defeat the entail. By the Fines and Recoveries Act, the technicalities formerly necessary in order to bar an entail were removed, and tenant in tail may now, by a simple conveyance, alienate his estate at pleasure. An estate tail is a freehold of a limited description. Tenant in tail may commit Waste (q. v.). Formerly, an estate tail was not liable to the debts of the tenant, but by 1 and 2 Vict. c. 110, this restriction has been removed. Copyhold lands have been held not to fall under the operation of the statute De Donis. A limitation, therefore, which in a freehold creates an estate tail, in copyhold lands creates a fee-simple conditional, according to the old common law, except where the custom of the manor is to the contrary.

In Scotland, as in England, entails appear first to have taken their rise from the feudal usages. It has been observed by Lord Kames, that while the feudal system was in its vigour, every estate was in fact entailed, because no proprietor had any power to alter the order of the succession. But when the stricter feudal principles gave way, and the power of alienating land began to be recognised, the holders of estates sought to secure, by deed, in their own families the lands which they possessed. The form urst adopted for this purpose was the simple destination, whereby the estate was simply limited to a particular series of heirs, without prohibition to alienate, or declaration of forfeiture for contravention of the will of the grantor. In this form, the deed must have resembled the early English entails. The feudal law of primogeniture having been received as a principle of common law, the estate would naturally descend from father to son in the line indicated by the deed. But, as it was held that those succeeding under this deed were not restrained from alienating, the practice of adding prohibitory clauses was introduced. Entails in this form were held to bind the heir from granting gratuitous alienations; but he was not restrained from selling the estate, or burdening it with debt. Early in the 17th c., a further addition was made to the form of the deed by the introduction of irritant and resolutive clauses, i. e., clauses declaring the act of alienation to be null, and to infer the forfeiture of the estate. The form thus adopted, which resembles closely the form of the Roman deed already noticed, was fortified by a decision of the Court of Session in the Stormont entail, M. 13994, holding that an estate so protected could not be attached by creditors. This decision created much difference of opinion amongst lawyers as to the power of the grantor thus to protect an estate from the onerous act of the heir, in consequence of which the famous Scotch Entail Act, 1685, c. 22, was passed, by which it was enacted that an estate conveyed by a deed fortified by prohibitory, irritant, and resolutive clauses, and recorded in a particular register, should be effectually secured in the line of destination. This act has always been most strictly viewed by Scottish lawyers; and entails which have been found deficient in any of the prescribed requisites, have been regarded by the courts as utterly ineffectual. The first Lord Meadowbank, in a judgment which has always been regarded as a leading authority, laid it down that entails are the mere creatures of statute,' and that where the interests of third parties are concerned, every part of an entail is liable to the strictest interpretation (Hamilton v. Macdowall, 3d March 1815). The operation of the old entail act was found, notwithstanding, to be of the most oppressive character. Statutes were in consequence passed from time to time, empower ng heirs of entail to grant leases of their Lands of longer duration than could be granted

under the act 1685, and to make provisions for their families. But at length, by the 11th and 12th Vict. c. 36, the power of fettering lands by a strict entail has been finally destroyed. By this act, heirs under an existing entail may disentail, with the consent of certain heirs next in succession; and in all entails made after 1st August 1848, and also in old entails where the heir in possession was born since 1st August 1848, the heir of entail in possession may, by means of a simple deed of disentail, free his estate from the restrictions of the entail.

In America, before the rebellion, the English law as to estates tail prevailed. But in the United States, the law of entails has been gradually abandoned by the several states; and property can now be fettered, to a limited extent only, by means of executory Devises (q. v.). In France, the power of creating entails has varied much at different periods, from the right to make a perpetual entail, which appears to have been the original principle, to a limitation to four, and at one time to two degrees. But by the Code Napoleon, ss. 896-897, entails are now absolutely prohibited. In Spain, also, entails, which were permitted under certain restrictions, have been entirely abolished by a law of the Cortes in 1820. Thus it will be seen that the right of securing land in a particular family, which commends itself to the natural feelings, has been found so oppressive in operation, and so injurious to the public interest, that after an existence of more than 600 years it has been practically discarded almost simultaneously by the general consent of modern nations.

E'NTASIS (Gr.), the swelling outline given to the shaft of a Column (q. v.).

ENTELLUS MONKEY, or HONUMAN (Semnopithecus Entellus), an East Indian species of monkey, with yellowish fur, face of violet tinge, surrounded with projecting hairs, long limbs, and very long muscular and powerful-though not prehensile tail. It is held in superstitious reverence by the Hindus, and is often to be seen exhibiting much impudent familiarity in the precincts of temples; indeed, temples are often specially dedicated to it; hospitals are erected for its reception when sick or wounded. Hindu laws affix à far more severe punishment to the slaughter of one of these sacred monkeys than of a man; the peasant

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Entellus Monkey (Semnopithecus Entellus).

esteems it an honour when his garden is plundered or his house robbed by troops of them, and would consider it an act of the greatest sacrilege to drive them away. They take their places with perfect confidence on the roofs of houses, and gaze at the passing crowd. This is one of the very few species

ENTERITIS-ENTOMOLOGY.

of monkeys found in the northern provinces of India, and in summer ascends the Himalaya to the pine-forests, and almost to the snow-line; it has even succeeded in crossing the mountains, and occurs in Bhotan.

ENTERITIS (Gr. enteron, the intestines), inflammation of the bowels, and especially of their muscular and serous coat, leading to Constipation (q. v.) and pain, with Colic (q. v.), and sometimes Ileus (q. v.). Enteritis is distinguished from these last affections, indeed, only by the presence of inflammatory symptoms-i. e., pain, tenderness, fever, &c., from a very early stage of the disease, and in so decided a form as to require special attention. If enteritis does not depend upon mechanical obstruction, it may be combated by hot fomentations, with moderate leeching and counter-irritation, and the internal administration of opium. Injections of warm water, or of asafoetida and turpentine (see CLYSTER), should be at the same time given to clear the lower bowel; and all purgatives, except in some cases castor oil, should be avoided. The disease is, however, one of great danger, and should never be incautiously treated with domestic remedies. It is closely allied to Peritonitis (q. v.), and often depends upon internal mechanical causes, or on external injury.

In the Lower Animals.-Inflammation of the bowels, among the heavier breeds of horses, generally results from some error of diet, such as a long fast followed by a large, hastily devoured meal, indigestible or easily fermentable food, or large draughts of water at improper times. When thus produced, it is frequently preceded by stomach staggers or colic, affects chiefly the mucous coat of the large intestines, and often runs its course in from eight to twelve hours. With increasing fever and restlessness, the pulse soon rises to 70 or upwards, and, unlike what obtains in colic, continues throughout considerably above the natural standard of 40 beats per minute. The pain is great, but the animal, instead of recklessly throwing himself about, as in colic, gets up and lies down cautiously. Respiration is quickened, the bowels torpid. Cold sweats, stupor, and occasionally delirium, precede death. When connected with, or occurring as a sequel to influenza, laminitis, and other complaints, the small intestines are as much affected as the large, and the peritoneal as well as the mucous coat of the bowels. This form is more common in the lighter breeds. When the patient is seen early, whilst the pulse is still clear and distinct, and not above 60, and the legs and ears warm, bloodletting is useful, as it relieves the overloaded vessels, and prevents that exudation of blood which speedily becomes poured out in the interior of the bowels. This disease should be treated as follows: In a pint of oil, or an infusion of two drachms of aloes in hot water, give a scruple of calomel and an ounce of laudanum, and repeat the calomel and laudanum every hour in gruel until the bowels are opened, or five or six doses are given. Encourage the action of the bowels by using every half hour soap and water clysters, to which add laudanum so long as pain and straining continue. If the animal is nauseated and stupid, with a cold skin, and a weak quick pulse, bleeding and reducing remedies are very injurious; and the only hope lies in following up one dose of the calomel and aloes with small doses of laudanum and sweet spirit of nitre, or other stimulants, repeated every forty minutes. In all stages, woollen cloths wrung out of hot water and applied to the belly encourage the action of the bowels, and relieve the pain.

Enteritis in cattle is mostly produced by coarse

wet pasture, acrid or poisonous plants, bad water, and overdriving. The symptoms are fever and thirst, a quick but rather weak pulse, restless twitching up of the hind limbs, tenderness of the belly, and torpidity of the bowels. Calves generally die in three or four days, other cattle in a week or nine days. Bleed early, open the bowels with a pint of oil and a drachm of calomel, which may be repeated in eight or ten hours, if no effect is produced. Give every hour fifteen drops of Fleming's tincture of aconite in water, until six or seven doses are given. Allow only sloppy and laxative food, such as treacle, gruel, or a thin bran mash; employ clysters and hot cloths to the belly, and use two-ounce doses of laudanum if the pain is great. Enteritis in sheep mostly occurs in cold exposed localities, and where flocks are subjected to great privations or improper feeding. The symptoms and treatment resemble those of cattle.

ENTOMOLOGY (Gr. entomon, an insect, logos, a discourse), the science which has INSECTS (q. v.) for its subject. The mere collector of insects may be one of the humblest labourers in the great field of natural history, but his labours contribute materials for the more philosophic naturalist who studies the structures of these creatures, and compares them with one another according to the unity and the variety of design which they exhibit. And when we begin to take into account the vast number of different species of insects, their great diversities of structure and of habits, their great complexity of organisation, the wonderful transformations which many of them undergo at different stages of their existence, and the equally wonderful but extremely various instincts which many of them display, we find entomology to be a science worthy to engage the noblest mind. But besides all these things, we must remember that insects serve most important purposes in the general economy of nature; and that some of them are directly useful to man, some directly injurious, at least when their numbers are at any time excessively multiplied.

Entomology, along with the other branches of natural history, was cultivated by Aristotle and other Greeks. Aristotle is the most ancient author of whose works anything relating to this science now remains. Pliny has little on this subject but what is copied from Aristotle; and it can scarcely be said to have been again studied as a science till the 16th c., when attention began once more to be directed to it, although it was not till the 17th c. that much progress was made, or that any important works on entomology appeared. Insects then began to be described, not only those of Europe, but also some of the curious and splendid insects of tropical countries; bees and other insects of particular interest received attention; the metamorphoses of insects began to be studied, and their anatomy to be investigated. The names of Goedart, Malpighi, Swammerdam, Leuwenhoek, and Ray deserve to be particularly mentioned; but the infant state of the science may be illustrated by the fact, that about the end of the 17th c., Ray estimated the whole number of insects in the world at 10,000 species, a number smaller than is now known to exist in Britain alone. In the 18th c., the name of Linnæus occupies as high a place in the history of entomology as in that of kindred branches of science. The progress of the science was much promoted by his arrangement and exhibition of the discoveries of previous and contemporary naturalists; and by his system of classification, founded on characters taken from the wings, or their absence, a system professedly artificial, yet so harmonising with the most natural distribution into groups, that some of its orders were indicated by

ENTOMOSTRACA-ENTOPHYTES.

Aristotle, and that it has retained and seems likely to retain its place, modified, indeed, but not essentially changed. De Geer and Fabricius are perhaps, after Linnæus, the most worthy to be named of the great entomologists of the 18th century. At the close of the 18th and beginning of the 19th c., the name of Latreile is pre-eminently conspicuous; and in the year 1815, a new impulse began to be given to the study of entomology in Britain by the publication of the admirable Introduction to Entomology of Messrs Kirby and Spence, a work combining in a remarkable degree the merits of being at once popular and scientific. Since the beginning of the 19th c., the number of insects known and described has prodigiously increased; many entomologists have with great advantage devoted themselves particularly to the study of particular orders of insects; and many valuable monographs have appeared. Entomological literature has now become very extensive. The progress of the science has owed not a little to entomological societies, of which the Entomological Society of London may be particularly mentioned. We cannot attempt to enumerate the distinguished entomologists of the 19th c., but perhaps the names of Leach, Macleay, Curtis, Stephens, Westwood, Smith, Walker, Stainton, Swainson, and Chuckard, deserve particular notice among those of Britain; Meigen, Jurine, Gyllenhal, Gravenhorst, Hubner, Dufour, Boisduval, Erichsen, and Lacordaire among those of the continent of Europe; and Say among those of America. It is to be regretted that we have not yet any complete work on the insects of Britain. The Insecta Britannica, of which some volumes by different authors have been published under the auspices of the Entomological Society, is intended to supply the want.

ENTOMO'STRACA (Gr. insect-shells), a term introduced by Müller, and adopted by Latreille, Cuvier, and other naturalists, to designate the second of their two great divisions of Crustaceans (q. v.). The number of species of E. is very great. They are all of small size, except the King-crabs (Limulus), which in many respects differ from all the rest, and have recently been formed by some naturalists into a sub-class of crustaceans by themselves. Many of them are minute, and exist in great numbers both in fresh and salt water, particularly in stagnant or nearly stagnant fresh water, affording to many kinds of fishes their principal food. They differ very much in general form; the number of organs of locomotion is also very various-in some very few, in some more than one hundred-usually adapted for swimming only, and attached to the abdominal as well as to the thoracic segments; but there never is a fin-like expansion of the tail, as in some of the malacostracous crustaceans. The antennæ of some are, however, used as organs of locomotion. Some of the E. have mouths fitted for mastication, and some for suction. Not a few are parasitic. The heart has the form of a long vessel. One or two nervous knots or globules supply the place of a brain. The organs of respiration are in certain species attached to some of the organs of locomotion, in the form of hairs, often grouped into beards, combs, or tufts, or blade-like expansions of the anterior legs are subservient to the purpose of respiration in others, no special organs of respiration are known to exist. The eyes are sometimes confluent, so as to form a single mass-one eye-in the front of the head. The name E. has been given to these creatures in consequence of most of the species having shells of one or two pieces, rather horny than calcareous, and of very slender consistence, generally almost membranous and transparent. In very many, the shell consists of two valves, capable of being completely closed, but which, at the pleasure of the

little animal, can also be opened so as to permit the antennæ and feet to be stretched out.

The study of the smaller crustaceans has recently been prosecuted with great assiduity and success. by Milne-Edwards and others; and in consequence of the great differences existing among them, new classifications have been proposed, and the name E. has by some been restricted to those which have a mouth formed for mastication, but no special organs of respiration, forming a section which is subdivided into two orders, Ostrapoda and Copepoda, the former having a bivalve shell or shield, the latter destitute of it. But the name E. is still commonly employed in its former wider sense.

ENTOMOSTRACA, FOSSIL. E. attained their tenanted in vast shoals. The Silurian Trilobite maximum size in the palæozoic waters, which they (q. v.) was a phyllopod, and the Pteregotus (q. v.) of the old red sandstone was nearly allied to the modern limulus. Small bivalvular species are found in all strata, sometimes, as at Burdie-House, near Edinburgh, forming layers of considerable thickness,

at others scattered in enormous numbers in the

dried sediments of lakes, as in the fresh-water clays of the Wealden, or forming in some places a large proportion of chalk, with the multitudes of their thin calcareous coverings.

E'NTOPHYTES (Entophyta; Gr. enton, within, and phyton, a plant), a term usually employed to denote those parasitic plants which grow on living animals. It is seldom extended to vegetable parasites which grow on living vegetables, whether on external or internal parts, nor is it restricted to those which are found in the internal cavities, or Iwithin the substance of animal bodies, but includes all which have their seat on living animal tissues. It does not, like the analogous term Entozoa, denote any particular class of organised beings; some of the E. are Alge, and some Fungi, but to these two orders they are limited, and all of them belong to the lower sections of these orders; some of them to those lowest sections in which the distinguishing characters of the two orders cannot easily be traced, so that they are referred to the one or the other on very slender grounds; those in which a colouring matter is present being reckoned algae, although it can be observed only in masses of aggregated cells, and not in the cells when viewed separately, and those which even in the mass appear entirely colourless, being considered fungi. Many of the alga and fungi parasitic on plants are nearly allied to those which occur on animals; thus, ergot and the kind of mildew which has proved so destructive to vines, are referred to the same genus (Oidium) to which is also referred the fungus found in the diseased mucous membrane in cases of aphthe or thrush and another genus (Botrytis, q. v.) contains the fungus called Muscardine, or Silkworm Rot, so destructive to silkworms, together with the fungus which accompanies or causes the potato disease, and many other species which infest plants. Common mould is even supposed to occur on animal tissues tending to decay, during life, as well as on dead animal and vegetable substances.

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Vegetable parasites occur both in man and in the lower animals; not a few of them are peculiar to fishes, and more are peculiar to insects than to any other class of animals. The fungi which grow on the bodies of insects sometimes attain an extraordinary development: Sphæria Sinensis, which grows on a Chinese caterpillar, and to which medicinal virtues, probably imaginary, are ascribed in China, attains a length greater than that of the caterpillar itself. A similar species (S. Robertsii) is found on the caterpillar of a New Zealand moth.

ENTOPHYTES-ENTOZOA.

The situations in which E. occur are very various. Some, like the thrush fungus already noticed, appear in diseased conditions of the mucous membrane; some find their place in the lungs, the ear, or other organs; some on the skin, in the hair follicles, and in as well as on the hair itself. The 'fur' which appears on the tongue when the stomach is disordered, abounds in the extremely slender unbranching threads of the alga called Leptothrix buccalis, which also vegetates luxuriantly in cavities and corners of the teeth not sufficiently visited by the tooth-brush. The lungs of birds, the gills of fishes, the intestines of insects, the wing-covers of beetles, the eggs of molluses, all have their peculiar vegetable parasites by which they are sometimes infested.

It is often by no means easy to say whether the presence of E. is to be regarded as the consequence or as the cause of disease; sometimes it may be both. Sometimes it appears to be certainly a consequence, as when the Sarcina (or Merismopædia) ventriculi occurs in the contents of the stomach and bowels; sometimes, as in the diseases called Favus, Porrigo, Tinea, Herpes tonsurans, Plica Polonica, Mentagra, Pityriasis versicolor, &c., it seems entitled to be regarded as the cause of the diseased state, and the cure of the disease seems to be accomplished by killing the parasite, often a thing of no little difficulty.

Whence the germs of E. are derived is often a question to which it would not be easy to find an answer. Their spores are extremely minute; but there are no plants which produce seeds or spores more abundantly than some of them do; the growth of the plants themselves is very rapid, and reproduction is very intense and rapid.'

It has sometimes been imagined that epidemic diseases may be caused by spores of E. conveyed through the air; no evidence has, however, been produced to render this opinion probable. An attempt was made to establish the existence of cholera fungi or algae, but it completely failed.'

ENTOZO'A. This term is applied to all the animal forms which live either in the natural cavities (as, for example, the intestinal canal), or in the solid tissues (as, for example, the liver) of other animals. The number of these parasites is so great (there being at least 20 distinct species of worms found in man, 14 in the dog, 15 in the horse, 11 in the common fowl, &c.), and their Occurrence so frequent, especially in some of the lower animals, that we must regard their presence, at all events in many species, rather as the normal condition, than as a morbid state due to accidental

causes.

It is worthy of notice, that many of the animals included amongst the E. only enjoy a parasitic existence during a part of their total life, which often, as in the well-known case of perfect insects, presents very varied and distinct phases. Thus, for example, the larvæ of the gadily (Estrus equi) undergo their entire development in the stomach of the horse, attaching themselves by minute hooks to the gastric mucous membrane; they then detach themselves, pass along the intestines, and in due time are discharged, and undergo their further changes externally; and many similar instances might be quoted. For this reason, and additionally because parasites are now known to belong to various classes of animals, we no longer attempt, like Linnæus and Cuvier, to form a special group of E.; and a reference to the Vermes intestine in the Systema Nature, or to the Entozoaires in the Règne Animal, at once shews that these illustrious naturalists grouped together animals with few or no true natural affinities.

Although most E. belong to the class of Vermes, or Worms, this, as has been already observed, is by no means exclusively the case. Thus, even fishes may lead a parasitic existence; a fish of the genus Fierasfer being frequently found in the respiratory cavity of the Holothuria tubulosa, or Sea-cucumber, and small fishes having been frequently observed in the cavity of the Asteria discoides. Amongst the crustaceans, instances of parasitism are by no means rare; different species of Lernæa being abundant in the branchial (or gill) cavity, and on the surface of numerous fishes, while the Linguatula infest mammals, reptiles, and fishes, being found in the olfactory sinuses, the larynx, the lungs, the peritoneal cavity, &c. The instances in which molluscs are found to live parasitically are few; certain gasteropods, however, inhabit the bodies of echinoderms, holothurias, and comatulas; and amongst the lamellibranchiates, species of modiolaria and mytilus live in the bodies of ascidians. There are several cases of polyps which have been observed to adopt a parasitic existence; and finally, various protozoa are not unfrequently met with in the animal fluids; for example, certain species of Vibrio, Cercomonas, and Paramecium, have been found in the intestinal evacuations in cholera and diarrhea; Monads have been found in the urine in cholera, and certain infusoria and rhizopoda in the blood of the dog, the frog, and many other animals. See HEMATOZOA.

The more common kinds of E. appear to have attracted the notice of the earliest physicians and naturalists whose opinions or works have reachedus. Hippocrates speaks of several worms, especially the tæniæ and ascarides, infesting the human intes tinal canal; and Pythagoras learned in India that the bark of the pomegranate acted almost as a specific in cases of tape-worm. Aristotle noticed both the tape-worm of the dog and of man, and the Cysticercus cellulose (see CESTOID WORMS) of the pig; but utterly unconscious that the cysticercus, under favourable conditions, became developed into a tape-worm (see TAPE-WORMS), referred the origin of all intestinal worms to spontaneous generation -a doctrine that seems to have been generally adopted till the 17th c., when Redi published (in 1684) a work on Helminthology, in which he dis tinctly shewed that the generation of various E. followed the same laws as in higher animals, and that in many instances there were distinct males and females. The great recent discovery, that the vesicular or bladder-like parasites, such as the different species of cysticercus and conurus, are cestoid worms in an early stage of development, is alluded to in CESTOID WORMS, and will be more fully noticed in the article TAPE-WORMS.

Another point of general interest in connection with E., is the part of the body in which they are found. While most live in the intestinal canal and other open cavities (as the larynx, bronchial tubes, &c.), others are found in the closed cavities and in the parenchymatous tissue of the liver and other solid organs. Thus (confining our remarks to the E. occurring in man), Anchylostoma duodenale, Strongylus duodenalis, two species of Ascaris, Oxyuris vermicularis, Trichocephalus dispar, Distoma heterophyes, at least four species of Tania, and Bothriocephalus latus, have been found in different parts of the intestinal canal; while Strongylus gigas inhabits the kidney, another species of Strongylus the lungs, a species of Spiroptera the bladder, two species of Filaria and Monostoma Lentis the eye, Trichina spiralis the voluntary muscles, two species of Echinococcus and Cysticercus cellulosa, various parenchymatous tissues, two species of Distoma the gall-bladder, another species the portal vein, and

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