Till H 



tion upon itself of the activity of mil or plant." * 



ii of a blacksmith in one which develops 

 the muscles of the arm by the continuous and vi^unni- 

 form of exercise of hamm< i ;n- th< blacksmith 



has a son who becomes a bookkeeper, does the son have 

 ii{ht arm than he would have had if his 

 fatlu-r ha.l been an office clerk! Ortainly the size of 

 a urn-el.- i- in< reasetl by use, and decreased size results 

 from disuse. Are these effects inh.-rited by the off- 

 igf One point must be noted carefully: the fact 

 th<> blacksmith does "develop strong muscles as 

 a result of the exercise shows that he must have an in- 

 born cai for developing strong muscles by exer- 

 But if tlu blacksmith "inh< -nt-d from his parents 

 the ability i lop strong muscles" by exercise, his 

 son in turn \\ouhl inherit from him the same ability. 1 " 

 rcise or tin- lark of it wouhl therefore only bring out 

 the I. :id-ney or simply leave the natural I 

 to work it- It out. The innate capacity would be in- 

 herited, not the accentuated development induced hy ex- 

 iiild is not the child of tin- biceps muscle 

 of tl. t. but the child of the germ cells of the par- 

 biceps muscle of tin- ha- little 

 these germ cells. How therefore, could the use of 

 ns muscle in the arm of the parent so affect the 

 otTvprini: that he would have stronger biceps than if his 

 nt had not developed his own through exercise? 

 ra is little evidence to support the doctrine of trans- 

 mission of acquired c <*s. 



But if thriv is no din emission of the individual 



modifications produced by environment, wherein does 

 the importance of function and < nvironm, nt consist! 



pp. 7*77. 



