520 CAROLINE BURLING THOMPSON 



with the different-sized compound eyes, and that the most signifi- 

 cant parts, the mushroom bodies, are of nearly similar bulk in 

 the second and third forms and in the soldier, and are only slightly 

 larger in the first form. The brain of the soldier of Termopsis, 

 sHghtly smaller than two reproductive castes and about equal to 

 another, is, therefore, when compared with the soldier brains of 

 higher termites, a relatively large brain. In short, this soldier 

 brain has not varied far from the primitive type of the genus — 

 the first form — and lacks the degenerate or specialized features 

 characteristic of the soldiers of higher termites. The interesting 

 correlation between the size of this soldier brain and that of the 

 almost sterile reproductive organs will be pointed out below. 



The hypodermis of the frontal surface of the head of the soldier 

 of Termopsis is not differentiated into a frontal gland as in the 

 nymphs and adults of the first form. The specimens sectioned 

 were young white soldiers, but with well-developed heads covered 

 by a fairly thick cuticle. No sections were made of adult soldier 

 heads on account of the very thick cuticle. 



In the abdomen, the four enteric caeca of the soldier are not 

 of similar size, as in the reproductive forms, but the two dorsal 

 caeca are shghtly larger than the ventral pair. 



The female reproductive system. The reproductive system of 

 the female soldier of Termopsis angusticolhs presents some of the 

 most interesting features of this study. In long-headed but 

 colorless soldier nymphs, with probably only one more molt to 

 undergo, the ovaries are smaller than in the nymphs of any of 

 the reproductive castes of about similar age. The egg tubes are, 

 however, numerous, but the eggs are small, only three or four eggs 

 at the lower or distal ends of the tubes having begun to enlarge 

 (fig. 20). These shghtly enlarged eggs are surrounded by distinct 

 egg foUicles. 



The egg tubes of each ovary are continued forward in threads 

 of connective tissue which unite and form a deUcate strand, the 

 terminal filament, which in turn runs to the anterior end of the 

 abdomen, spreading out into a brush of fibers at its point of 

 attachment. The terminal filament occurs in the ovaries of all 

 the castes of this species, but is seen to best advantage in the 



