264 THE INDUCTIONS OF BIOLOGY. 



fittest, been adjusted in the proportions and qualities of its 

 parts to a given function. If the multiplying protoplasts, 

 instead of taking equal portions of chromatin, have some of 

 them smaller portions, the parts of the organ formed of 

 these, developing less rapidly and having inferior energies, 

 will throw the organ out of adjustment, and the individual 

 will suffer in the struggle for life. That is to say, irregular 

 division of the chromatin will introduce a deranging factor 

 and natural selection will weed out individuals in which it 

 occurs. Of course no interpretation is thus yielded of the 

 special process known as karyokinesis. Probably other 

 modes of equal division might have arisen. Here the argu- 

 ment implies merely that the tendency of evolution is to 

 establish some mode. In verification of the view that equal 

 division arises from the cause named, it is pointed out to 

 me that amitosis, which is a negation of mitosis or karyo- 

 kinesis, occurs in transitory tissues or diseased tissues or 

 where degeneracy is going on. 



But how does all this consist with the conclusion that the 

 chromatin conveys hereditary traits — that it is the vehicle in 

 which the constitutional structure, primarily of the species 

 and secondarily of recent ancestors and parents, is repre- 

 sented? To this question there seems to be no definite 

 answer. We may say only that this second function is not 

 necessarily in conflict with the first. While the unstable 

 units of chromatin, ever undergoing changes, diffuse energy 

 around, they may also be units which, under the conditions 

 furnished by fertilization, gravitate towards the organization 

 of the species. Possibly it may be that the complex com- 

 bination of proteids, common to chromatin and cytoplasm, is 

 that part in which the constitutional characters inhere; 

 while the phosphorized component, falling from its unstable 

 union and decomposing, evolves the energy which, ordinarily 

 the cause of changes, now excites the more active changes 

 following fertilization. This suggestion harmonizes with the 

 fact that the fertilizing substance which in animals consti- 



