62 Bulletin American Museum of Natural History. [Vol. XXIII^ 



may resemble bees in some respects, do not react in a similar way to the 

 bee to meagreness of nutrition, and that accordingly this mode of reaction 

 is a characteristic of bees: — it is a new acquisition, and was not possessed 

 by the ancestors of these insects." 



The views of the more active European myrmecologists, Emery,. 

 Escherich, Forel and Wasmann, are in close accord with those of Weismann, 

 but there are some significant departures, especially in Emery's view, which 

 approaches that of Spencer. Emery gives this summary of his position in 

 a paper on the origin and development of the worker among ants:^ "The 

 theory which I have attempted to carry out in hypothetical form, is based 

 on the assumption, that the production of the worker depends on the in- 

 stinctive art of breeding workers, and that the origin of the worker caste 

 is to be attributed more to a difference in the quality, the differentiation of 

 several kinds of workers more to the quantity of the food. From the latter 

 process I would not, of course, exclude the possible play of qualitative 

 factors; their intervention is, indeed, probable in specific cases, such as, 

 e. g., in the Melissotarsus beccarii, which I have described, and which has 

 two kinds of workers of the same size but with heads of a different form. 



" The peculiarities in which the workers differ from the corresponding 

 sexual forms are, therefore, not innate or blastogenic, but acquired, that is 

 somatogenic. Nor are they transmitted as such, but in the form of a pecul- 

 iarity of the germ-plasm that enables this substance to take different devel- 

 opmental paths during the ontogeny. Such a peculiarity of the germ may 

 be compared with the hereditary predisposition to certain diseases, which 

 like hereditary myopia develop only under certain conditions. The eye 

 of the congenitally myopic individual is blastogenetically predisposed to 

 short-sightedness, but only becomes short-sighted when the accommodation 

 apparatus of the eye has been overtaxed by continual exertion. Myopia 

 arises, like the peculiarities of the worker ants, as a somatic affection on a 

 blastogenic foundation. 



"With this assumption the problem of the development of workers seems 

 to me to become more intelligible and to be brought a step nearer its solution. 

 The peculiarities of the Hymenoptera workers are laid down in every female 

 egg; those of the termite workers in every egg of either sex, but they can 

 only manifest themselves in the presence of specific vital conditions. In 

 the phylogeny of the various species of ants the worker peculiarities are not 

 transmitted but merely the faculty of all fertilized eggs to be reared as a 

 single or several kinds of workers. The peculiar instinct of rearing workers 



1 Die Entstehung und Ausbildung des Arbeiterstandes bei den Ameisen. Biol. Centralbl., 

 XIV, 1894, pp. 58, 59. 



