IV. 



Neuter Insects and Darwinism. 



MR. PLATT BALL (5) does not think that Herbert Spencer's reply 

 (2) to Weismann's argument concerning neuter insects, in the 

 Contemporary controversy, is convincing, and he adduces certain new 

 points to which he thinks Spencer's arguments do not apply. I propose 

 to examine again the questions in dispute, and to try to ascertain how 

 much weight is to be attributed to Mr. Ball's contribution to the 

 discussion. I do not propose to take the question of use-inheritance 

 as my chief point, but to consider what are the most logical conclu- 

 sions we can draw from the facts before us as to the explanation of 

 the phe^nomena presented by social polymorphic insects, or those in 

 which several forms are produced by one parent. As I have no original 

 knowledge of these insects, 1 intend to take the facts chiefly as 

 they are accepted and presented by the three disputants above 

 mentioned. 



Weismann (i) limits himself to the phenomena presented by ants. 

 He says that it may be taken for granted that the ant workers have 

 arisen through phyletic metamorphosis of fruitful females. What 

 other origin could they have had ? he asks. As evidence of this he 

 mentions that to this day there are some species in which the workers 

 closely resemble the females, and that in other cases intermediate 

 forms have frequently been found. This is the most extraordinary 

 assumption with which to begin his argument, for the one thing 

 obvious and certain is that the ant workers have not arisen by the 

 phyletic metamorphosis of fruitful females. The very fact that the 

 workers are sterile precludes this assumption. They are the 

 daughters and sisters of fruitful females, not the offspring of parents 

 possessing their own peculiarities. No animal can be said to have 

 arisen by phyletic metamorphosis from its mother ; and as all the 

 ancestors of the neuter ants were fruitful females, it is difficult to see 

 where the phyletic metamorphosis comes in. None of these ances- 

 tors have exhibited degrees of modification which lead to the 

 peculiarities seen in the workers. 



Whether the natural selection of females which have possessed in 

 different degrees the property of generating workers adapted to their 

 work is the true explanation of the evolution of the workers, that is 

 the question I am about to consider. But to call this hypothetical 



