EN'TOPHYTES (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 within 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 organized beings; some of the E. are algte, and sonic 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 coloring matter is present being reckoned aim 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 colorless, being consider6d fungi. Many of the algte 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 aphth(e 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 mold is even supposed to occur on animal tissues tending to decay, during life, as well as on dead animal and vegetable substances.
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: splueria 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.
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 mollusks, 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 merismopce) diaventriculi occurs in the contents of the stomach and bowels; sometimes, as in the diseases called lams, porrigo, tinea, herpes tonsurans, plica polonica, mentagra, pityriasis versicolor, etc., 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 grow th of the lants 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 air; Lo 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.