116 THE ADVANCE OF SCIENCE 



of similar structure, called cells, each cell 

 having its own life independent of the 

 others, though influenced by them. 



All the morphological characters of ani- 

 mals and plants are the results of the mode 

 of multiplication, growth, and structural 

 metamorphosis of these cells, considered 

 as morphological units. 



All the physiological activities of ani- 

 mals and plants — assimilation, secretion, 

 excretion, motion, generation — are the ex- 

 pression of the activities of the cells con- 

 sidered as physiological units. Each in- 

 dividual, among the higher animals and 

 plants, is a synthesis of millions of subor- 

 dinate individualities. Its individuality, 

 therefore, is that of a ' civitas ' in the 

 ancient sense, or that of the Leviathan of 

 Hobbes. 



There is no absolute line of demarca- 

 tion between animals and plants. The 

 intimate structure, and the modes of 

 change, in the cells of the two are funda- 



