44 HABITS OF WORMS. CHAP. I. 



the protoplasmic contents of the cells, we 

 may infer that it resembles in nature not 

 saliva,* but pancreatic secretion ; and we 

 know from Fredericq that a secretion of this 

 kind is found in the intestines of worms. As 

 the leaves which are dragged into the bur- 

 rows are often dry and shrivelled, it is in- 

 dispensable for their disintegration by the 

 unarmed mouths of worms that they should 

 first be moistened and softened ; and fresh 

 leaves, however soft and tender they may be, 

 are similarly treated, probably from habit. 

 The result is that they are partially digested 

 before they are taken into the alimentary 

 canal. I am not aware of any other case of 

 extra-stomachal digestion having been re- 

 corded. The boa-constrictor is said to bathe 

 its prey with saliva, but this is doubtful ; and 

 it is done solely for the sake of lubricating its 

 prey. Perhaps the nearest analogy may be 

 found in such plants as Drosera and Dionaea ; 

 for here animal matter is digested and con- 

 verted into peptone not within a stomach, but 

 on the surfaces of the leaves. 



Claparede doubts whether saliva is secrete*! by worms : see 

 Zeitschrift fur wissenschaft. Zoologie,' B. xix. 1869, p. 601. 



