WINGLESS REPRODUCTIVE TYPE OF TERMITES 593 
In regard to the developing nymphs, Grassi recognized Lespés’ 
‘nymphs of the first form’ and ‘nymphs of the second form,’ 
but evidently believed that, taken young enough and with proper 
treatment, any nymph might be changed into anything else. 
In order to simplify the rather confused and at present mis- 
leading nomenclature of Grassi and others, one of the writers 
(Thompson, 717) has proposed that the three reproductive 
castes, with long wings, short wing vestiges, and no wings, should 
be termed, respectively, in conformity with Lespés’ terminology 
for nymphs, adults of the first, second, and third form. This 
terminology will be used in the present paper. 
It was also proposed that the nymphs of the wingless repro- 
ductive form of R. flavipes, which were then unknown, should, 
if discovered later, be termed nymphs of the third form. These 
nymphs have since been found by one of the writers (T. E. 8.), 
and have been studied and positively identified as such by the 
other writer (C. B. T.). 
When the third-form queens of R. flavipes and R. virginicus 
Banks were first found and described (Snyder, 15), and for some 
time after, they were considered as of rare or infrequent occur- 
rence, but so many specimens have been collected recently by 
one of the writers (T. E. 8.) that it may be stated with certainty 
that the third forms of Reticulitermes flavipes, virginicus, and 
tibialis Banks are not uncommon. 
A full account of the morphology of the nearly mature nymph 
and adult of the third form of R. flavipes will be given below. 
The close external resemblance to workers shown by these partly 
mature third-form nymphs at first suggested that the third form 
might be merely a fertile worker, but after careful study, this 
view has been abandoned in favor of the opinion that the third 
form of Reticulitermes is a distinct morphological caste. 
To reach this opinion a careful comparison has been made of 
the third form of R. flavipes with the other castes of this species. 
Similar studies were made with species in four other genera of 
termites: the Antillean termite, Prorhinotermes simplex Hagen,” 
Termopsis from the Pacific coast, Neotermes and Kalotermes 
2 Formerly Arrhinotermes simplex. See Banks and Snyder, ’19. 
