FUNGI. 351 
the mucous membrane of the intestinal canal in 
which they grow ; and from their delicate structure 
they must be more or less constantly liable to 
rupture in the peristaltic movements of the bowels, 
and the passage onwards of the food ; but from 
the spiral arrangement of one species, and the sig- 
moid flexure of another, these graceful filiform 
plants may be elongated or stretched onwards for 
a considerable distance without danger of being 
torn. The economy of these plants is altogether 
peculiar ; existing as they do under circumstances 
totally different from those in which all other 
plants are found, and in this respect strikingly 
illustrative of the wonderful capacities of vegetable 
life. That vegetable life can exist within animal 
life is an extraordinary circumstance ; but a cir- 
cumstance still more extraordinary in connexion 
with their history is, that many of these entophytes 
are developed upon entozoa, or animals within 
animals, and are in their turn the seat of other 
parasitic entophytes more minute, while even on 
these parasitic entophytes themselves are produced 
still more minute forms of vegetation. We have 
thus within the microscopic compass of a beetle’s 
body an epitome of what takes place on a large 
scale throughout the world of sense and sight— 
life supported by life to the third and the fourth 
degree. These parasite and parasitic-parasite 
