8 B. GRASSI AND A. SANDIAS. 



appear at first sight to be less numerous in young substitute 

 and in perfect queens ; but this is deceptive, because many are 

 so far arrested in growth as to be with difficulty made out. 

 The remainder of the female generative organs (PI. 18, fig. 10) 

 present no marked differences from those of Calotermes.^ 



In Termes alike the number of testicular follicles is difficult 

 to count, but is about eight (PI. 18, figs. 5 — 8). Neither in 

 this nor in any other respect is there any difference between 

 the sexual organs of the substitute and of the perfect king.' 



Spermatozoa are present in Termes lucifugus in the 

 spermatheca (in small quantity, from 150 to 1000 in round 

 numbers) and vasa deferentia, just as in Calotermes. For 

 examination they were collected by preference from the sperma- 

 theca (PL 18, fig. 9). Their form is round, about 2 to 4 |U in 

 diameter. The immature spermatozoa in the testis possess a 

 tail, which is lost as they ripen. They are also non-motile. 



The degree of development of the generative organs in 

 examples in process of becoming substitute kings or queens 

 varies concomitantly with the stadium in which they are. In 

 Calotermes, in which the phenomena can be better followed, 

 I find that the development of the gonads proceeds very slowly 

 in the royal substitutes, and that the pigmentation of the com- 

 pound eyes is almost always the earliest diagnostic character. 

 The female genital appendices are usually shed at the next 

 succeeding ecdysis. 



I have spoken of the substitute forms in course of growth, 

 but which have not yet moulted, as larvse of such forms ; they 



^ In Termes numerous unicellular glands, each furnished with a cuticular 

 duct, are crowded under the columnar epithelium of the spermatheca and 

 open into its lumen (PI. 19, fig. 6). I have not examined Calotermes for 

 them. The accessory colleterial glands are two in number, one usually long 

 and full of secretion, the other shorter and narrower, its secretion being 

 generally very scanty. 



These glands have a common aperture in connection with the ninth true 

 sternite, whilst that of the vagina, into which the spermatheca opens, is 

 in the eighth true sternite. These observations apply to Termes only. 



2 The intromittent organ is wanting, and the male genital opening lies in 

 the ninth true sternite. 



