TRANSMISSIBILITY OF FUNCTIONAL MODIFICATIONS 89 



distinguished naturalists, and most of their vital functions have 

 been precisely studied. Ever since the days of ' Old Peter Huber ' in 

 Geneva there have again and again been excellent observers who 

 have devoted almost the whole of their life-work and talents to the 

 more complete study of these wonderful animals. These insects are 

 of interest to us here, because, in the course of the social life, a type 

 of individual has arisen which diverges in structure in many parts 

 of the body from both the male and the female, although it is sterile 

 and does not reproduce, or does so in so few instances that the fact 

 is of no moment in considering the origin of the present bodily 

 structure. As is well known, these neuters, or better, workers, 

 are, among ants and bees, females which differ from the true females 

 not only in their smaller size and their infertility, but in many other 

 points as well. Among ants, for instance, they are absolutely wing- 

 less, and at the same time they have a much smaller and differently 

 formed thorax and a larger head. But the most striking point is 

 the diff'erence in their instincts, for while the females, concerned only 

 with reproduction, pair and lay eggs, it is the workers who feed 

 and clean the helpless emerging larvae, and put them in places of 

 safety, who carry the pupae into the warm sunshine, and afterwards 

 back again to the sheltered nest, who make this nest itself, and keep 

 it in order, after having collected or prepared the material for it ; 

 it is they alone who defend the colony against the attacks of enemies, 

 who undertake predatory expeditions, attacking the nests of other 

 ants, and engaging in obstinate combats with them. 



How can all these peculiarities have arisen, since the workers 

 do not reproduce, or do so only exceptionally, and, in any case, are 

 incapable of pairing, and therefore — among bees at least — only pro- 

 duce male offspring'? Obviously it cannot have been through the 

 transmission of the effects of use and disuse, since they leave no 

 offspring to which anything could be transmitted. 



Herbert Spencer has attempted to maintain the position that 

 the characters of the workers of to-day already existed in the pre- 

 social state, that is, before the ants began to form colonies, and that, 

 therefore, they have not been newly evolved but only preserved. 

 But, even if this be conceded in regard to the care of the brood 

 and the building instinct, so much remains that could not have 

 existed at that stage, that the problem of the origin of these new 

 characters remains unsolved. The wings, for instance, among ants, 

 can only have been lost when females appeared which did not repro- 

 duce, for the pairing of ants is associated with a nuptial flight high 

 in the air. The wings are not merely absent in the workers, they 



Digitized by Microsoft® 



