56 Life and Immortality. 
digestible matter it may contain. Large numbers of half- 
decayed leaves of all kinds, excepting a few that are too 
tough and unpleasant to the taste, and likewise petioles, 
peduncles, and decayed flowers. Fresh leaves are consumed 
as well. Particles of sugar, licorice and starch, and bits of 
raw and roasted meat, and preferably raw fat, are eaten when 
they come into their possession, but the last article with a 
better relish than any other substance given to them. They 
are cannibals to a certain extent, and have been known to 
eat the dead bodies of their own companions. 
The digestive fluid of worms, according to Leon Frédéricq, 
is analogous in nature to the pancreatic secretion of the 
higher animals, and this conclusion agrees perfectly with the 
kinds of food which they consume. Pancreatic juice emul- 
sifies fat, dissolves fibrin, and worms greedily devour fat and 
eat raw meat. It converts starch into grape-sugar with 
wonderful rapidity, and the digestive fluid of worms acts 
upon the starch of leaves. But worms live chiefly on half 
decayed leaves, and these would be useless to them unless 
they could digest the cellulose forming the cell-walls, for all 
other nutritious substances, as is well known, are almost 
completely withdrawn from leaves shortly before they fall 
off. It has been ascertained that cellulose, though very little 
or not at all attacked by the gastric juice of the higher 
animals, is acted on by that from the pancreas, and so worms 
eat the leaves as much for the cellulose as for the starch 
they contain. The half-decayed or fresh leaves which are 
intended for food are dragged into the mouths of their bur- | 
rows to a depth of from one to three inches, and are then 
moistened with a secreted fluid, which has been assumed to 
hasten their decay, but which, from its alkaline nature, and 
from its acting both on the starch-granules and on the proto- 
plasmic contents of the cells, is not of the nature of saliva, 
but a pancreatic secretion, and of the same kind as is found 
in the intestines of worms. As the leaves which are 
dragged into the burrows are often dry and shrivelled, it is 
