334 KANSAS UNIVERSITY SCIENCE BtJLLETIN. 



ninth segment, where it passes around the cereal nerve and a 

 few strands of muscle and ligament (figs, 7 and 8). Making 

 a sharp bend it goes forward and ventralward. It is very 

 much coiled upon itself from the bend on (figs. 7 and 8). The 

 loops of the coils may lie in planes passing dorso-ventrally or 

 laterally. The two vasa deferentia join and immediately empty 

 into the posterior ventral angle of the sinus, which receives 

 the openings of the annexed glands (fig. 9). Beginning at 

 the cereal nerve and sometimes a little in front of the bend 

 the duct is swollen so as to be 0.5 to 0.75 mm. in diameter 

 (figs. 7 and 8). Fenard says there are from four to five coils 

 and that the total length is 8 mm. In our common field cricket 

 I found no regularity about the position or number of coils 

 and the total length is more than 10 mm. 



This swollen part of the vas deferens is always in the mature 

 adult filled with a mass of sperm, all of them with their heads 

 turned away from the testis. 



Fenard (^) , as well as the older investigators, says that "the 

 union of the two vasa deferentia forms the ejaculatory duct." 

 This is the statement generally made of the insects higher in 

 the scale of evolution ; but it is true only in a certain sense — in 

 the sense that it serves as a common duct to carry out the 

 secretions of the testes. First, it is not a true ejaculatory 

 duct in the sense that it "during coition conducts the sperm 

 into the copulatory pouch of the female" — Packard {18). 

 This is true only in those insects with a penis; but in the 

 Gryllidae, where there is a spermatophore formed there can be 

 no such function. Second, nor is it true in the sense that it is 

 formed by a growing together of the two vasa deferentia. It 

 is formed by an invagination from the outside, as was first 

 shown by Palmen {17) from the anatomical standpoint and by 

 Nusbaum {16) from the embryological. This invagination 

 projects quite far beyond the point at which the two vasa def- 

 erentia join it (fig. 7). It extends dorsalward and forward, 

 where it receives the openings of the hundreds and hundreds of 

 tubules of the annexed glands (fig. 9). The lumen is very 

 much flattened laterally and widened vertically towards the 

 blind end. The more muscular tube leaves the sinus at the 

 posterior dorsal angle just above the point of entrance of the 

 vasa. This is well shown in figure 9. The openings of the vasa 

 cannot be recognized in this figure, but the serial section's leave 

 no doubt as to its location. 



