16 



Life and Death, Heredity and Evolution 



Figure 2. Some of the more complex Protozoa. A, Caenomorpha 

 medusula Perty, after Biitschli. B, Didinium capturing prey, after 

 Balbiani. C, Vorticella nebulifera O. F. M., after Biitschli. 'D, Fol- 

 liculina, after Mobius. E, Stentor roeselii Ehr., after Stein. F, Lacry- 

 maria olor, after Verworn. G, Stylonychia mytilus Ehr., after Engel- 

 mann. 



animals. The interest of their study lies partly in dis- 

 covering what life can do with few differentiated structures. 

 Moreover, it seems clear that in their general plan of struc- 

 ture they are comparable to single cells of higher animals, 

 though, like such single cells elsewhere, they may be very 



