PROCESS OF REPRODUCTION IN ORGANISMS. 33 



plays so importanc a part in recent biological hypothesis. What 

 is the chromosome? If it is what many authors seem to believe, 

 it is an autonomous being endowed with something more than 

 human intelligence. But if we are not willing to believe this, 

 then we must regard the chromosome as an incident or result 

 of dynamic processes in the organism, like other morphological 

 entities. If this is the correct view, then it is nothing ultimate 

 or fundamental. We must analyze it into terms of the processes 

 which have made it and in this analysis we shall sooner or later 

 find nothing more nor less than the whole complex of processes 

 which constitute the organism. The organism makes the chromo- 

 somes, not the chromosomes the organism. 



Montgomery ('06, p. 56) has said that we understand heredity 

 so far as we know the behavior of chromosomes. To my mind 

 the exact opposite of this statement is much more nearly true. 

 The reappearance of chromosomes in successive generations of 

 cells is itself as truly a special problem in inheritance as the re- 

 appearance of any other characteristic morphological feature of 

 an organism, e. g., the fingers of the hand, the hand itself, etc. 

 Moreover, to state the problems of inheritance in terms of 

 chromosomes is nothing more than a statement and not a solution 

 of the problem, and besides this it cannot be a complete nor a 

 correct statement. 



The experimental data of recent years on heredity are very 

 commonly regarded as supporting and confirming the germ plasm 

 hypothesis. And particularly the at least doubtful character 

 of much of the evidence bearing upon the inheritance of acquired 

 somatic characters is considered as a strong indication of the 

 independence of the germ plasm and the soma. It seems to me, 

 however, that the real problem is obscured by our ignorance 

 or misconception of the nature of inheritance. A very laige 

 proportion, if not most of the individually acquired somatic 

 characters, are due to changes in metabolism which are primarily 

 quantitative, not qualitative in character. Such quantitative 

 changes in the dynamic processes in the organism are dependent 

 upon actually existing internal or external environmental con- 

 ditions and cannot be expected to persist indefinitely after the 

 conditions which produced them are no longer present. As a 



