5 8 Life and Immortality. 



of the calciferous glands, it is likely that they primarily 

 serve as organs of excretion, and secondarily as an aid to 

 digestion. Worms consume many fallen leaves. It is known 

 that lime goes on accumulating in leaves until they drop off 

 the parent-plant, instead of being re-absorbed into the stem 

 or roots, like various other organic and inorganic substances, 

 and worms would therefore be liable to become charged with 

 this earth, unless there was some special apparatus for its 

 excretion, and for this purpose the calciferous glands are ably 

 adapted. On the other hand, the carbonate of lime, which 

 is excreted by the glands, aids the digestive process under 

 ordinary circumstances. Leaves during their decay generate 

 an abundance of various kinds of acids, which have been 

 grouped together under the term of humus acids. These 

 half-decayed leaves, which are swallowed by worms in large 

 quantities, would, therefore, after having been moistened and 

 triturated in the alimentary canal, be apt to produce such 

 acids, and in the case of several worms, whose alimentary 

 canals were examined, their contents were plainly shown by 

 litmus paper to be decidedly acid. This acidity cannot be 

 attributed to the nature of the digestive fluid, for pancreatic 

 juice is alkaline, and so also is the secretion which is poured 

 out of the mouths of worms for the preparation of the leaves 

 for consumption. With worms not only the contents of the 

 intestines, but their ejected matter or the castings are gener- 

 ally acid. The digestive fluid of worms resembles in its 

 action, as already stated, the pancreatic secretion of the higher 

 animals, and in these latter pancreatic digestion is necessarily 

 alkaline, and the action will not take place unless some alkali 

 be present; and the activity of an alkaline juice is arrested 

 by acidification, and hindered by neutralization. Therefore 

 is seems probable that innumerable calciferous cells, which 

 are emptied from the four posterior glands in the alimentary 

 canal, serve to neutralize more or less completely the acids 

 generated there by the half-decayed leaves. These cells, as 

 has been seen, are instantly dissolved by a small quantity of 



