600 CAROLINE B. THOMPSON AND THOMAS E. SNYDER 
After swarming is over, mates are chosen, the wings are shed, 
breaking along the lines of the ‘humeral suture,’ and the subter- 
ranean life begins. The sex organs mature and in time become 
the largest of any caste. 
The enlarged adults of the first form. After a period of time, 
probably within two years, the abdomen enlarges in those first- 
form adults which have mated, and its size then increases with 
the age of the individual, but especially so in females. As the 
abdomen grows the color of the chitinized dorsal and ventral 
plates becomes a light golden brown, and the non-chitinized 
unpigmented portions increase enormously, so that in the oldest 
males and females the abdomen is a huge whitish sac with nine 
pairs of small yellowish plates indicating the former segments. 
The body length of these enlarged adults ranges from 7 to 14.5 
mm. Sections show that the space within the abdomen of the 
female is chiefly filled by the enormously increased ovaries, and 
by oenocytes, glandular, and fatty tissue. The muscles, especi- 
ally the jaw muscles in the head, degenerate and their place is 
filled by fatty tissue. This degeneration of the jaw muscles is 
due to the fact that the reproductive forms are now fed by the 
workers on partly digested food and no longer masticate wood 
as they were compelled to do before the first broods of workers 
were raised. Mature females of the first, second, or third forms 
do not survive in captivity unless enough workers are present to 
feed them. 
The second form of R. flavipes 
The second form, like the first, is found in three phases of 
development: a) the nymphs of the second form, with short 
wing pads, and colorless body and eyes; b) the young adults of 
the second form, with short scaly wing vestiges, and straw colored 
or grayish body 6 to 7 mm.;c) the older adults of the second form, 
with wing vestiges, and enlarged abdomen 7 to 12 mm 
The nymph of the second form. Soon after hatching, as stated 
above, the young nymphs of the second form may be distinguished 
microscopically from those of the first form by their slightly 
smaller brain and sex organs. When they have attained a body 
length of 4 mm. the shorter wing pads may be recognized. 
