114- THE PROGRESS OF SCIK"- n 



morphology, development, and physiology. Thanks 

 to the immense series of labours thus inaugui 

 the following fundamental truths have 

 established. 



All living bodies contain substances of closely 

 similar physical and chemical composition, which 

 constitute the physical basis of life, known as 

 protoplasm. So far as our present knowledge 

 goes, this takes its origin only from pre-existing 

 protoplasm. 



All complex living bodies consist, at one period 

 of their existence, of an aggregate of minute 

 portions of such substance, of similar structure, 

 called cells, each cell having its own life indepen- 

 dent of the others, though influenced by them. 



All the morphological characters of animals 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 animals and 

 plants assimilation, secretion, excretion, motion, 

 generation are the expression of the activities of 

 the cells considered as physiological units, 

 individual, among the higher animals and plants, 

 is a synthesis of millions of subordinate indi- 

 vidualities. Its individuality, therefore, is that 

 of a"civitas" in tin- ancient sense, or that of the 

 Leviathan of Hobbes. 



There is no absolute line ol'dcniareatioii l>et 



