30 COMPARATIVE ZOOLOGY. 



sessed by protoplasm, and so by all animals : all move, 

 feel, and grow. But some of the lowest forms are with- 

 out the slightest trace of organs ; they seem to be as per- 

 fectly homogeneous and structureless as a drop of jelly. 

 They could not be more simple. They are devoid of 

 muscles, nerves, and stomach ; yet they have all the fun- 

 damental attributes of life moving, feeling, and eating. 

 It has been supposed that the muscular and nervous mat- 

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

 that the highest power of the microscope reveals no organ- 

 ized 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 stom- 

 ach : in other words, life is the cause of organization, not 

 the result of it. Animals do not live because they are or- 

 ganized, but are organized because they are alive. 



CHAPTER Y. 



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 



