312 WILLIAM MORTON WHEELER 
any rate, as an aid, in insuring cross-fertilization. The fecun- 
dated queen of the ant-colony represents the first link in the 
‘Keimbahn’ and therefore corresponds to the fertilized egg of the 
personal organism. She produces both the worker personnel and 
the virgin males and females, just as the fertilized egg produces 
both the soma and the germ-cells. The colonial soma, moreover, 
may be differentiated as the result of a physiological division of 
labor into two distinct castes, comprising the workers in which the 
nutritive and nidificational activities predominate, and the sol- 
diers, which are primarily protective. Here, too, the resemblance 
to the differentiation of the personal soma into entodermal and 
ectodermal tissues can hardly be overlooked. 
The structure of the ant-colony thus appears to be very simple 
as compared with that of its component persons. The question 
naturally arises as to the particular type of unicellular or per- 
sonal organism which it most resembles. Undoubtedly, if we 
could see it acting in its entirety, the ant-colony would resemble 
a gigantic foraminiferous Rhizopod, in which the nest would rep- 
resent the shell, the queen the nucleus, the mass of ants the 
plasmodium and the files of workers, which are continually going 
in and out of the nest, the pseudopodia. 
The ant-colony, of course, like the person, has both an onto- 
genetic and a phylogenetic development; the former open to 
observation, the latter inferred from the ontogeny, a comparison 
of the various species of ants with one another and with allied 
Hymenopterous insects, and from the paleontological record. 
The fecundated queen, as I have stated, represents the fertilized 
egg which produces the colonial organism, but she is a winged and 
possibly conscious egg, capable not only of actively disseminating 
the species, like the minute eggs of many marine animals, but of 
selecting the site for the future colony. After finding this site 
she discards her wings and henceforth becomes sedentary like the 
wingless workers which she will produce. The whole colony rests 
satisfied with the nesting site selected by its queen if the environ- 
mental conditions remain relatively constant. If these become 
unfavorable, however, the colony will move as a whole to a new 
site. In most species such movements are rather limited, but the 
