WINGLESS REPRODUCTIVE TYPE OF TERMITES 607 
abdomen of the workers and soldiers. In sections of the abdo- 
mens of the different castes the cause is clearly seen. The spaces 
of the body cavity between the viscera are filled, in all three 
reproductive castes, by dense masses of fat cells; in the sterile 
forms there are fewer of these masses of fatty tissue and many 
more spaces. This also accounts for the firm texture and outline 
noted for the abdomen of the reproductive forms and for its 
looser texture in the worker and soldier. 
In third-form nymphs with a body length of 4.5 mm. or less 
the three fundaments of the female reproductive system—ovary 
and oviducts, seminal receptacle and proximal part of the vaginal 
duct, colleterial gland and distal part of the vaginal duct—are 
found as separate parts, not yet fused, an embryonic condition 
characteristic of all young nymphs and of adult workers and 
soldiers (Knower, ’01) (figs. 27, 28). 
The parts of the female reproductive system of a third-form 
nymph of 5 to 5.5 mm. are complete’y fused although not yet 
of full size. The ovaries (fig. 23) contain eggs which show signs 
of growth, the seminal receptacle is large, and the vaginal duct 
hasalumen. The colleterial gland is small, though convoluted. 
In the male (fig. 26) the testes are large and lobed, in size sur- 
passing those of the first form, the vasa deferentia and the seminal 
vesicles are convoluted, and the muscular penis is well developed. 
Here is another important distinction between the third form 
and the worker, the former with fully developed and functional 
sex organs (figs. 6, 28, 26), the latter with these organs in a 
vestigial and non-functional condition (figs. 7, 27, 29). 
The contents of the alimentary canal furnish another difference 
_ between the two castes. The third form, like the other repro- 
ductive castes, is evidently fed on predigested food furnished by 
the worker and does not masticate wood, for the large intestinal 
sac, the ‘caecum,’ is always clear and free from the dark woody 
masses found in the worker. The parts of the digestive system 
differ slightly in size in the different castes, and the salivary 
glands are larger in the reproductive forms than in the two sterile 
castes. 
The young adult of the third form. The young adult differs 
from the nearly mature nymph just described chiefly in size and 
