THEORY OF THE DEVELOPMENT OF ORGANISMS 131 



the existence of transitional forms presents no 

 difficulty on the theory of the agency of food. But 

 how can the doctrine of determinants be applied 

 to it ? ' If he is consistent ' (says Spencer, Con- 

 temporary Revieiv, Ixiv., p. 901), ' he must say that 

 each of these intermediate forms of workers must 

 have its special set of " determinants," causing its 

 special set of modifications of organs ; for he cannot 

 assume that while perfect females and the extreme 

 types of workers have their different sets of deter- 

 minants, the intermediate types of workers have 

 not. Hence we are introduced to the strange con- 

 clusion that, besides the markedly distinguished 

 sets of determinants, there must be, to produce 

 these intermediate forms, many other sets slightly 

 distinguished from one another a score or more 



o 



kinds of germplasm, in addition to the four chief 

 kinds. Next comes an introduction to the still 

 stranger conclusion, that these numerous kinds of 

 germplasm producing these numerous intermediate 

 forms are not simply needless, but injurious 

 produce forms not well fitted for either of the 

 functions discharged by the extreme forms, the 

 implication being that natural selection has origin- 

 ated these disadvantageous forms. If, to escape 

 from this necessity for suicide, Professor Weismann 

 accepts the inference that the differences among 

 these numerous intermediate forms are caused by 

 arrested feeding of the larvae at different stages, 

 then he is bound to admit that the differences 

 between the extreme forms, and between these and 

 perfect females, are similarly caused. But if he 



