52 HABITS OF WORMS. Chap. I. 



" going on in the contents themselves. . . . 

 " In Carnivora the contents of the coecum 

 " are said to be alkahne, and naturally the 

 " amount of fermentation will depend largely 

 " on the nature of the food."* 



With worms not only the contents of the 

 intestines, but their ejected matter or the 

 castings, are generally acid. Thirty castings 

 from different places were tested, and with 

 three or four exceptions were found to be 

 acid ; and the exceptions may have been due 

 to such castings not having been recently 

 ejected ; for some which were at first acid, 

 were on the following morning, after being 

 dried and again moistened, no longer acid ; 

 and this probably resulted from the humus 

 acids being, as is known to be the case, easily 

 decomposed. Five fresh castings from worms 

 which lived in mould close over the chalk, 

 were of a whitish colour and abounded with 

 calcareous matter ; and these were not in 

 the least acid. This shows how effectually 

 carbonate of lime neutralises the intestinal 

 acids. When worms were kept in pots filled 



* M. Foster, * A Text-Book of Physiology,' 2nd edit. 1878, 

 p. 243. 



