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 Fredericq, 

 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 completely withdrawn from leaves shortly before they fall 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 



