30 COMPARATIVE ZOOLOGY. 



all animals: all move, feel, grow, and multiply. But some 

 of the lowest forms are without the slightest trace of or- 

 gans ; they seem to be as perfectly homogeneous and struct- 

 ureless as a drop of jelly. They could not be more sim- 

 ple. They are devoid of muscles, nerves, and stomach ; 

 yet they have all the fundamental attributes of life mov- 

 ing, feeling, eating, and propagating their kind. It has 

 been supposed that the muscular* and nervous matter is 

 diffused in a molecular form ; but all we can say is, that 

 the highest power of the microscope reveals no organized 

 structure whatever i. e., there are no parts set apart for a 

 particular purpose, but a fragment is as good as the whole 

 to perform all the functions of life. The animal series, 

 therefore, begins with forms that feel without nerves, 

 move without muscles, and digest without a stomach, pro- 

 toplasm itself having all these properties : in other words, 

 life is the cause of organization, not the result of it. Ani- 

 mals do not live because they are organized, but are organ- 

 ized because they are alive. 



CHAPTER V.* 



ORGANIZATION. 



WE have seen that the simplest life is a formless speck 

 of protoplasm, without distinctions of structure, and there- 

 fore without distinctions of function, all parts serving all 

 purposes mouth, stomach, limb, and lung indiscrimi- 

 nately. There is no separate digestive cavity, no separate 

 respiratory, muscular, or nervous systems. Every part 

 will successively feed, feel, move, and breathe. Just as in 

 the earliest state of society all do everything, each does 

 all. Every man is his own tailor, architect, and lawyer. 

 But in the progress of social development the principle of 

 * See Appendix. 



