STUDIES IN ANIMAL LIFE. 21 



feeding while we have been lecturing. At the men- 

 tion of feeding you naturally look for the food that 

 is eaten, the mouth and stomach that eat. But I 

 hinted just now that this ethereal creature dispenses 

 with a stomach, as too gross for its nature, and of 

 course, by a similar refinement, dispenses with a 

 mouth. Indeed, it has no organs whatever except 

 the cilia just spoken of. The same is true of several 

 of the Infusoria, for you must know that naturalists 

 no longer recognize the complex organization which 

 Ehrenberg fancied he had detected in these micro- 

 scopic beings. If it pains you to relinquish the 

 piquant notion of a microscopic animalcule having 

 a structure equal in complexity to that of the ele- 

 phant, there will be ample compensation in the 

 notion which replaces it, the notion of an ascending 

 series of animal organisms, rising from the struc- 

 tureless amoeba to the complex frame of a mammal. 

 On a future occasion we shall see that, great as 

 Ehrenberg's services have been, his interpretations 

 of what he saw have one by one been replaced by 

 truer notions. His immense class of Infusoria has 

 been, and is constantly being, diminished; many 

 of his animals turn out to be plants ; many of them 

 embryos of worms ; and some of them belong to 

 the same divisions of the animal kingdom as the 

 oyster and the shrimp that is to say, they range 

 with the Mollusks and Crustaceans. In these, of 

 course, there is a complex organization ; but in the 

 Infusoria, as now understood, the organization is 



