1929] 
Human and Insect Societies 
185 
which supplies the raw materials of food and shelter build- 
ing. While there is a fundamental difference between the 
methods used by men and insects to re-create the group, the 
methods used by each to exploit the trophoporic field do not 
differ fundamentally. There are two methods used: the 
actual collection from the field of the materials needed (in 
the insects by foraging for what can be found) , by develop- 
ment, as the growth of fungi and the “domestication” of 
aphids by ants; in man, foraging, (not common), and 
development, (farming, mining, etc.), and the taking by 
force of the materials collected by other groups. The second 
method is dependent upon the first, and is essentially non- 
social when it means the exploitation of parts of a society 
by other parts. Of course, one society may legitimately be- 
come a part of the trophoporic field of another, as the 
keeping of bees by man, or the eating of a library by 
termites. (There is no reason, from a termite point of 
view, for respecting the possessions of man). And in each 
society, human and insect, the exploitation of the tropho- 
poric field is possible only by labor on the part of the in- 
dividuals of the society. 
Since the many activities necessary for efficient produc- 
tion can be carried out best by a specialization for part- 
icular tasks among the members of a society we find that 
there is a division of labor developed by both insects and 
men. The first most fundamental division of labor is, of 
course, the development of sex. This is found in both 
groups. But, as pointed out before, the insects have de- 
veloped a special caste that does nothing but reproduce, 
w r hile man has not. In the exploitation of the trophoric 
field, too, the insects have developed a caste, which has, to 
a great degree, lost its ability to reproduce, the worker 
caste. This sterile caste does all of the labor necessary for 
producing food, building the nest (except in the case of 
some insects where the primal sexual pair, or a single 
fertilized female, initiates the work of nest building) , caring 
for the reproductive caste (whose children they are), and 
caring for the new brood (their brothers and sisters). 
This division of labor has brought about an actual struct- 
ural difference between the reproductive and worker castes, 
