9 2 



ZOOLOGY 



The in- 

 heritance of 

 a dimple 



FIG. 21. The effect of environment on squash plants. The two plants shown were 

 grown at Boulder, Colorado, from the same lot of seeds. On the left, the ground 

 was left unfilled ; on the right, it was turned up and manured. Another squash, 

 from the same lot of seeds, growing just behind the big one, also had fertile soil, 

 and grew to a large size; but its fruits were green and worthless, because it was 

 crossed with some other kind. The large plants are those which have had ad- 

 vantages in this world; have been to college, as it were. But sometimes, if the 

 heredity is unfavorable, the environment is powerless to give satisfactory results. 



The route we pursue is in time strewn with the remains 

 of all that we began to be, of all that we might have 

 become. But Nature, which has at command an in- 

 calculable number of lives, is in no wise bound to make 

 such sacrifices. She preserves the different tendencies 

 that have bifurcated with their growth. She creates 

 with them diverging series of species that will evolve 

 separately." (Creative Evolution, page 99.) Heredity 

 provides the hand of cards, but ours may be the choice 

 to play. Does heredity also determine that choice ? 

 In part, yes, but as every one knows, it is very largely 

 determined by the influence of others, by opportunity, 

 and lines of least resistance. 



5. As an illustration of the force of heredity and its 

 independence of environment in certain cases, we may 

 cite the inherited dimple in the chin of the P. family. 

 The dimple is correlated with a depression in the bone 



