340 KANSAS UNIVERSITY SCIENCE BULLETIN. 



absent, while the stylet is well developed and projects far 

 backward. The cavity is smaller, making it necessary that 

 the plate of the spermatophore be bent into a smaller curve. 

 There are other minor differences in size and relations. 

 Whether these differences are great enough to prevent inter- 

 crossing of species is not positively settled. I tried some ex- 

 periments in cross-breeding, in which I was unable to get any 

 cross matings; but the tests were not extensive enough to be 

 very conclusive. 



IN NEMOBIUS. 



This genus resembles rather closely the form which Lespes 

 describes under the name Gryllus Sylvestris. It is much smaller 

 than our Gryllus and, like the European form, it likes the 

 woods or shady places ; in the grass under the trees of a park 

 I have found the most specimens. In the months of August 

 and September they are very numerous. 



In its courting it is, like the domestic cricket, much more 

 shy than the larger form, and it is rather tedious to watch till 

 one catches a pair copulating. In the main the whole series 

 of processes is quite similar to that in Gryllus. In the courting 

 the male is more active while the female less readily yields to 

 the courting. What Lespes {12) says of his forms holds true 

 for our two genera: "Except some details of form and size 

 all is similar. The spermatophore is smaller and more fragile 

 but is similarly composed. The genital armature presents the 

 same pieces, but they differ much in form." Lespes again in 

 this species figures and describes the thread as continuous with 

 the canal of the plate. This strengthens my belief that there 

 is some mistake in the description of the spermatophore of 

 Gryllus campestris. 



I have succeeded in getting a good photograph (fig. 4), that 

 shows the structure of the spermatophore of Nemobius fas- 

 ciatus, our most common species, very well. The ampulla is 

 almost a perfect sphere. Its wall is thick and its central cavity 

 rather small and nearly spherical. As in Gryllus sylvestris, 

 the plate is small and far from the ampulla, but the thread and 

 plate are much more curved in our species (fig. 4) . There is a 

 fine, hollow, tube-like opening leading from the central cavity 

 to the tip of the thread. There can be no doubt that the sperm 

 fluid flows out through it. 



