MODERN PHILOSOPHICAL BIOLOGY. 723 



sis. But agamo-gencsis is not habitual in organisms of very simple 

 structure, which exhibit the first steps in evolution, and in which 

 the absence of highly-specialized tissues shows that integration still 

 possesses its full intensity, and is far removed from equilibrium. Be- 

 sides, those more complex organisms which exhibit the phenomenon 

 of agamo-genesis, from time to time reproduce by way of gamo-gene- 

 sis. After a series of agamic generations, the units of the organism 

 will find themselves in an attitude approaching that of mutual equi- 

 librium. The groups of units emitted as germs will no longer be able 

 to assume arrangements which shall give them the form proper to 

 their species, and agamo-genesis will be impossible, or very difficult. 

 The series would come to an end did not sexual generation intervene 

 periodically, restoring a state of instability, which gives back to the 

 organism the power of evolution. Another conclusion, which at first 

 sight appears to contradict the facts, is this, that an organism needs, 

 in order to reproduction, the concurrence of another organism diifer- 

 ing slightly from it. This is true of the higher organisms ; but lower 

 down in the animal scale, and in most phanerogamous plants, her- 

 raaphrodism is apparently the rule. But, not to speak of the fact that 

 most frequentljt fecundation takes place in monoecious organisms by 

 the intervention of anotlier individual, so that such authors as Huxley 

 and Darwin regard this intervention as the law of reproduction, the 

 hypothesis which we maintain affords an explanation of hermaphro- 

 dism in those exceptional cases where it appears to exist beyond 

 question. On the same principles which account for the variable re- 

 sults of the union of near kindred, we can understand how, in the 

 case of hermaphrodites, there may exist simultaneously groups of 

 physiological units coming from each parent, keeping their proper 

 tendencies, which find only partial equilibrium, permitting one or 

 other side to be in excess, and there undergoing the operation of seg- 

 regation, which produces groups so differentiated that fruitful germs 

 result from their mixture. 



Considered in the light of this hypothesis, generation appears as a 

 fact of disaggregation, occurring in an organism in process of equili- 

 bration : as a fact of disaggregation, which ever renews the evolution 

 of the species, and which retards its equilibrium by multiplying the 

 conditions under which the species may, under the influence of the 

 incident forces of the environment, undergo a more perfect elabora- 

 tion, the result of which shall be a better adaptation of the organism 

 to its surroundings. Generation is in fact antagonistic to equilibrium, 

 but this antagonism is only temporary, and causes the organic evolu- 

 tion to obey the law of universal rhythm. 



\To be continued.'] 



