140 EVOLUTION 



formed in_SQfflie ,germ-cell of s 



t _ point of 



The issue at present seems to be this, that 

 there are character^ wjifch friend when 



Patient work is necessary in order 

 to test these two groups and to discover what 

 is the criterion of blending and alternating 

 respectively. In his interesting work on 

 "Hereditary Characters," Dr. Charles E. 

 Walker maintains the thesis that 



tend. to h lp H aT H th nf 



n r 



ORIGIN OF VARIATIONS. Since variations 

 form the raw materials of evolution, it 

 would be satisfactory if we could conclude 

 this chapter by stating how they arise. But 

 that is quite impossible at present. We 

 know very little that is certain in regard to 

 the originative factors in evolution. We 

 must still confess, with Darwin: "Our 

 ignorance of the laws of variation is pro- 

 found." It may be of interest, however, to 

 notice some of the suggestions that have 

 been made in regard to this fascinating 

 problem. 



There are variations which pnean aiigmen- 

 taliotU^or diminution, or re-^y^|]gempnf of 

 already exiting, .. qiialities . Now, if the 



