260 B. GRASSI AND A. SANDIAS. 
Calotermes flavicollis differs materially from Termes 
lucifugus in the fact that it confines itself to excavating 
burrows, and is thus merely a borer; whereas the latter 
species not only bores, but builds tunnels, in order to connect 
pieces of wood at a considerable distance apart. 
2. Number of Individuals in the Colony. 
In these observations a normal development of the colonies 
isassumed. For should the queen, for example, die before the 
community has reared a successor, several months pass during 
which oviposition is suspended and multiplication is conse- 
quently brought to a standstill. 
A colony of Calotermes rarely consists of more than a 
thousand members, and is relatively numerous when it contains 
five hundred. This is correlated with the fact that the queen 
of our species is very far from attaining the colossal dimen- 
sions which are well known to occur in the queen-termites of 
tropical countries. 
After fifteen months of common life the king and queen 
may be surrounded with fifteen or twenty young, after another 
year with about fifty, and in the two or three following years 
the population increases till it reaches a maximum at which it 
becomes nearly stationary. This is attained when the king 
and queen have reached the largest possible size. 
Eight or ten winged adults may depart from a two-year- 
old nest, and the number leaving in successive years increases 
concomitantly with the increase in the population. 
At the time of maximum oviposition a queen of three to 
four years old lays as a rule four, five, or six eggs a day. 
3. The Different Castes (Plate 16). 
By way of preliminary, it should be stated that for the sake 
of orderly arrangement a knowledge is assumed in this part 
of the work of certain conclusions, the demonstration of which 
is postponed to the succeeding chapter. 
A colony of Calotermites contains— 
1. Undifferentiated larve (fig. 1), capable of becoming 
