438 PROCEEDINGS OF THE ACADEMY OF [1893. 



less exacting character. In a second stage of evolution the com- 

 munity would present the character of a family of varied forms all 

 of whose members would produce any or all of the types of form to 

 be found in it, under slight diversities of condition, just as now, all 

 species produce young of two sexes. The differences between the 

 members of an ant community are considerable in appearance, but 

 not so great essentially as that between sexes. Finally, in a third 

 stage of the history, the function of reproduction came to be the 

 special office of a few members of the community. This may have 

 been due to a deficiency of food accessible to certain individuals 

 aborting the reproductive powers ; but whatever may have been 

 the cause, a majority of individuals became sterile. The repro- 

 ducing members of the community, however, have continued to pro- 

 duce all of the forms of the community. They produce sterile 

 workers and soldiers, sometimes of several forms, through heredi- 

 tary influences. But this, says Mr. Ball, is evidence that inherit- 

 ance can have no share in the process. He believes that each one 

 of the structural types of the community is produced by the treat- 

 ment accorded to the young by the workers, each generation for 

 itself. How excessive additions to structure can be produced by 

 starvation, he does not attempt to show. 



As we have seen that the embryonic and paleontologic histories 

 distinctly negative the idea that each generation has been produced 

 by itself without inheritance, let us endeavor to read the riddle in 

 the light of the knowledge we have gained from paleontology. We as- 

 sume that the most specialized types, the soldiers, represent the fer- 

 tile type of the species in Liassic time, when the family first appears, 

 or soon after. The process of change into workers and breeders has 

 been degenerative. In ants, as in the case of the many other animals, 

 slight differences in the supply of nutritive energy may prevent or 

 produce these degenerative processes, as it appears to do in the case 

 of the production of the sexes. (Experiments on lepidopterous larva? 

 have shown that excessive food supply produces females and deficient 

 supply produces males). In bees, the larvae of the female (queen) 

 receive the largest food supply; those of the males less; and those of 

 the neuters the least of all. How the food supply came to be varied 

 so as to produce the several types, in accordance with the exigencies 

 of the community, is a question to be solved by future research. 

 Perhaps it was due to variations in the supplies available at par- 

 ticular times of the year; and perhaps the ants thus acquired a habit 

 of feeding and came to practise it intelligently. It is enough for the 

 present purpose to have shown that it is more probable that the basis of 

 the entire community, the original fertile soldier, acquired his char- 

 acters in the usual way: by use, and that all other forms have been 

 derived from him by inheritance, modified by disuse or degeneracy, 

 under the influence of variations in the food supply. 



