1893.] NATUBAL SCIENCES OF PHILADELPHIA. 437 



heads, very powerful mandibles, and "extraordinarily different in- 

 stincts. In the driver ant of west Africa one kind of neuter is three 

 times the size of the other, and has jaws nearly five times as long. 

 In another case " the workers of one caste alone carry a wonderful 

 sort of shield on their heads. ' ' One of the three neuter classes in 

 the leaf-cutting ants has a single eye in the middle(?) of its forehead. 

 In certain Mexican and Australian ants some of the neuters have 

 huge spherical abdomens, which serve as living reservoirs of honey 

 for the use of the community. In the equally wonderful case of the 

 termites, or so-called "white ants," (which belong, however, to an 

 entirely different order of insects from the ants and bees) the neuters 

 are blind and wingless, and are divided into soldiers and workers, 

 each class possessing the requisite instincts and structures adapting it 

 for its tastes. Seeing that natural selection can form and maintain 

 the various structures and the exceedingly complicated instincts of 

 ants and bees and wasps and termites in direct defiance of the 

 alleged tendency to use-inheritance, surely we may believe that 

 natural selection, unopposed by use- inheritance, is equally competent 

 for the work of complex or social or mental evolution in the many 

 cases where the strong presumptive evidence cannot be rendered 

 almost indisputable by the exceptional exclusion of the modified 

 animal from the work of reproduction." 



"Ants and bees seem to be capable of altering their habits and 

 methods of action much as men do. Bees taken to Australia cease 

 to store honey after a few years' experience of the mild winters. 

 Whole communities of bees sometimes take to theft, and live by 

 plundering hives, first killing the queen to create dismay among the 

 workers. Slave ants attend devotedly to their captors, and fight 

 against their own species. Forel reared an artificial ant colony made 

 up of five different and more or less hostile species. Why cannot a 

 much more intelligent animal modify his habits far more rapidly and 

 comprehensively without the aid of a factor which is clearly unneces- 

 sary in the case of the more intelligent of the social insects." 



The explanation of this phenomenon will be probably some day 

 found by paleontologic discovery. We may suppose, on the basis of 

 discoveries already made in other animals, that the primitive ants and 

 termites presented homogeneous colonies, and that the varied struc- 

 tures which they present to-day have been primarily due to the usual 

 process of specialization through use-inheritance. It is reasonable to 

 suppose that the varied functions of the different members of the 

 community have modified the structures of the parts essential to their 

 performance. It is probable that the earliest ants in an early geo- 

 logic period, became soldiers under the usual exigencies of their 

 struggle for existence, and having thus secured a place in the 

 economy of nature, certain members of the communities underwent 

 degenerative changes, appropriate to their respective functions, of a 



