WINGLESS REPRODUCTIVE TYPE OF TERMITES 603 
enlarged second-form female is irregular or lumpy in outline, 
perhaps due to irregularities in. the development of the sex 
organs or fat bodies. The internal changes are similar to those 
noted for the first form: increase in size of the sex organs and 
the fatty and glandular tissues, and degeneration of most body 
muscles. 
The third form of R. flavipes 
The third form of R. flavipes has been found in the same three 
phases as the nymphs of the first and second form, namely: 
a) the nymphs of the third form, wingless, with pure white head 
and body, and eyes that are invisible in the living or unstained 
specimen; 6) the young adults of the third form, wingless, head 
and body pure white, opaque and not transparent, about 6 mm. 
long; c) the older adults of the third form with enlarged abdomen, 
wingless, head and body white, 7 to 9 mm. long. 
The enlarged adults of the third form of R. flavipes and R. 
virginicus have been known for several years (Snyder, 715, 716); 
the nymphs and the young third-form adults of R. flavipes have 
been only recently recognized as such, and are here described 
for the first time. The close resemblance of the living nymphs 
and young adults of the third form to the workers of their species 
is evidently the reason why this caste of Reticulitermes, except 
in the enlarged adult phase, has hitherto been overlooked. 
For many years, one of the writers (T. E. 8.) had noted that 
in certain colonies of species of Reticulitermes where there were 
numerous eggs and recently hatched young it was impossible 
to find any enlarged first, second, or even third reproductive 
forms. Nevertheless, in these colonies nymphs, worker-like 17 
form but with creamy white abdomens, often occurred. it was 
then suspected that these might be young reproductive forms 
of the third type. 
Only after careful study have criteria been found for distin- 
guishing the worker and third-form castes in R. flavipes and also 
in the related southern species R. virginicus. Since these criteria 
were established it is interesting to note that in looking over old 
