106 THE BEGINNINGS OF LIFE. 



But such things are not only true concerning the 

 germs of plants ; somewhat parallel phenomena are pre- 

 sented even by adult organisms in the animal series. 

 The c Sloths ' of Spallanzani, the Rotifers, and the Free 

 Nematoids or Anguillules, certainly should be taken into 

 account by those who would wish to arrive at correct 

 conceptions as to Life. These animals, having com- 

 paratively definite and complex organizations, are now 



FIG. i. Animals found in tufts of Moss and Lichen. 



a. Plectus parietinus, a Free Nematoid. 



b. Rotifer vulgaris, the common Wheel Animalcule. 



c. Emydium testudo, one of the ' Sloths ' of Spallanzani. 



notorious for their tenacity of Life, their power of re- 

 sisting the most adverse external conditions, and, 

 above all, for their power of resuming active vital mani- 

 festations, after these have been completely in abeyance 

 for five, ten, fifteen, or even more than twenty years ' . 



1 More complete details concerning these properties may be found in 

 a memoir on The Anatomy and Physiology of the Nematoids, Parasitic 



