THE CONSTITUTION OF MATTER. 19 



up of molecules in which the atoms are grouped in prisms, in 

 pyramids, in a word, in polyhedra more or less many-sided, 

 but always of perfect regularity ; so that, in this case, the 

 differentiation is regulated with marvelous harmony. 



We must now rise another degree, and pass from in- 

 organic matter to living matter. What is it that distin- 

 guishes the latter from the former ? When we make the 

 answer depend on the results of direct experiment, nothing 

 is easier than to establish the differential characteristics of 

 living matter. In the first place, it is organized, that is, the 

 anatomical elements, instead of being homogeneous and 

 symmetrical in all points of their mass, are composed by 

 the association of a certain number of different substances, 

 in which carbon predominates, and which are termed im- 

 mediate organic principles. 1 Then, these elements grow. 

 At no time the same throughout, as to the substance which 

 makes them up, they are in a state of unceasing molecular 

 renewal, of constant metamorphosis, of simultaneous and 

 continuous assimilation and disassimilation. Besides, the 

 various properties these elements may exhibit, contractility, 

 neurility, and so on, are, in consequence of the growing 

 state that characterizes them, in so unstable a condition of 

 equilibrium that the slightest variation in the surrounding 

 medium is enough to occasion some change in the expres- 

 sion of their activity ; in other words, they have excessive 

 excitability and irritability. Such, at least, is the region 

 within which physiology is limited ; but the fact which it 

 does not clearly enough bring out, yet the thing which is 

 the distinctive mark of life, is the harmonious seeking for 

 each other of all these vital monads, the disposition of 



1 " The structure of chemical compounds is subject only to mathemati- 

 cal laws, which laws do not control that of organized matter. In germs 

 and their products there exists a want of symmetry in their axes, which 

 indicates a formative purpose, or, more properly, a creative omnipotence." 

 GAUDIN, "Architecture of the World of Atoms," p. 3. 



