2IO MENDELISM chap. 



using it sifts, adds, and rejects, and passes it on to 

 the next a little better and a little fuller. When 

 we speak of progress we generally mean that the 

 hoard has been improved, and is of more service to 

 man in his attempts to control his surroundings. 

 Sometimes this hoarded knowledge is spoken of as 

 the inheritance which a generation receives from 

 those who have gone before. This is misleading. 

 The handing on of such knowledge has nothing 

 more to do with heredity in the biological sense than 

 has the handing on from parent to offspring of a 

 picture, or a title, or a pair of boots. All these 

 things are but the transfer from zygote to zygote 

 of something extrinsic to the species. Heredity, on 

 the other hand, deals with the transmission of some- 

 thing intrinsic from gamete to zygote and from 

 zygote to gamete. It is the participation of the 

 gamete in the process that is our criterion of what 

 is and what is not heredity. 



Better hygiene and better education, then, are 

 good for the zygote, because they help him to make 

 the fullest use of his inherent qualities. But the 

 qualities themselves remain unchanged in so far as 

 the gamete is concerned, since the gamete pays no 

 heed to the intellectual development of the zygote 

 in whom he happens to dwell. Nevertheless, upon 

 the gamete depend those inherent faculties which 

 enable the zygote to profit by his opportunities, and, 

 unless the zygote has received them from the gamete, 

 the advantages of education are of little worth. If 

 we are bent upon producing a permanent betterment 

 that shall be independent of external circumstances, 

 if we wish the national stock to become inherently 



