MODERN PHILOSOPHICAL BIOLOGY. 599 



those orsranic substances are formed which are the basis of living: 

 bodies. The belief which from day to day is gaining confirmation 

 from the labors of physiologists is that so boldly exj^ressed by Claude 

 Bernard, viz., that as the chemist, starting with the knoAvledge of in- 

 organic bodies, subjects them to his will and creates new bodies, so the 

 physiologist, starting from organic matter, " by imposing upon it 

 special conditions, will be able to produce new physiological modifi- 

 cations and new series of phenomena, thus modifying at will living- 

 bodies, and even creating them." 



At the same time, by comparing and analyzing the different 

 branches of biology, certain very general laws have been established, 

 particularly in physiology proper, having a bearing ujjon the develop- 

 ment of the individual and the relations of the functions to their or- 

 gans. We are in possession of a certain number of very broad though 

 purely empiric generalizations on the phenomena upon which the supe- 

 riority of living things over one another depends. These are, properly 

 speaking, laws of organic Nature. 



First, we have the law of the increase of the mass of the organism, 

 in virtue of which each living thing attains its full development only 

 by passing through a series of phases characterized by an augmenta- 

 tion of its mass, and consequently by an augmentation of the quantity 

 of force applicable for its physiological actions, as also by an augmen- 

 tation of the quantity of functional products. 



Then thei*e is the law of the multiplication of parts in proportion 

 as we ascend in the series of living things, this multiplication being 

 determined by an increase of complexity in the organic machine, in 

 virtue of the diversity both of the functions which make their appear- 

 ance and of the organs which result from this diversity of functions. 



Again, we have the law of courdination and subordination of func- 

 tions and organs, in virtue of which, in proportion as complexity is in- 

 troduced into the oroanism and as the functions and orsjans take on a 

 more special character, certain functions and the organs performing 

 them become dependent on other functions and other organs. Be- 

 sides, a tie of solidarity is established between all the parts of the liv- 

 ing body, so as to guide them toward a common end, the conserva- 

 tion of the individual, while at the same time all of the jjarts feel the 

 reverberation of the actions to which each is subject. 



Next comes the law of adaptation, in virtue of which an organism 

 tends to be so modified as to seem to be specially created to suit the 

 circumstances amid whicli it exists and the kind of life imposed upon 

 it by them. This law is still, for many thinkers, the basis of ideas 

 of final causes by means of which they strive to explain the structure 

 of livino: thinsrs and the variations observed therein. 



Finally, there is the law of heredity, in virtue of which organisms 

 produce new organisms which repeat their type. Heredity is the law 

 of fixity; it expresses the tendency to perpetuate a condition of things 



