318 ENTOMOLOGY 
Origin of Castes.—Grassi maintains that all the forms are 
alike at birth except as regards sex, and that the differences 
between worker and soldier, which are independent of sex, 
depend probably upon nutrition. Grassi attributes all the di- 
versities of caste, except the sexual ones, to the character and 
amount of the food. 
Food.—The food of termites is of six kinds: (1) wood: 
(2) matter emitted from the cesophagus or rectum, termed 
respectively stomodzeal and proctodzeal food; (3) cast skins 
and other exuvial stuff; (4) the bodies of their companions ; 
(5) saliva; (6) water. Of these the proctodzeal food is the 
favorite. Nymphs receive at first only saliva; later they get 
stomodzeal and proctodzeal food until, finally, they are able to 
eat wood—the staple food of a termite. 
American Species.—Our common termite is Termes flavi- 
pes, which occurs throughout the United States, excavating 
its galleries in decaying logs, stumps or other dead wood. The 
nuptial flight of this species takes place in spring, when the two 
sexes swarm in numbers that are sometimes enormous. One 
swarm, as recorded by Hagen, appeared as a dense cloud, and 
was being followed and attacked by no less than fifteen species 
of birds, among which were robins, bluebirds and sparrows; 
some of the robins were so gorged to the mouth with termites 
that their beaks stood open. Though plenty of winged fe- 
males are said to occur in the swarming season, a true queen 
of T. flavipes is as yet unknown, the queen described by Hub- 
bard being evidently, from her undeveloped wings, a substitu- 
tion queen. 
In the Western states, six species of termites are known, 1n- 
cluding Termes lucifugus, which has probably been introduced 
from Europe. In this species the primary queen is known to 
exist. Regarding the Californian Termopsis angusticollis, 
Dr. Heath says that if only one of the royal pair be destroyed 
usually only one substitution form is developed, but when both 
perish, from ten to forty substitutes appear, according to the 
size of the colony; furthermore—a remarkable fact—these 
