32 ANIMAL STUDIES 



same functions are performed by definite structures, the 

 cilia and gullet. Now, it is well known that a workman is 

 able to make better watch-springs, when this is his sole 

 duty, than another who must make all parts of the watch ; 

 and likewise, where a definite task is performed by a defi- 

 nite structure, it is more efficiently done than where any 

 and every part of the body must carry it on. So the 

 Ammba, in which definite tasks are performed by any part 

 of the body indifferently, is less perfect and thus lower than 

 the Paramceciurri) where these functions are performed by 

 special organs. As we ascend the scale of life we find this 

 division of labor among special parts of the body more 

 complete, the organs, and therefore the animal, more com- 

 plex, and better fitted to carry on the work of its life. 



