330 KANSAS UNIVERSITY SCIENCE BULLETIN. 



copulation. This intervening time was unusually short, 

 but I am sure that it does not take an hour for a spermato- 

 phore to harden after it is formed. 



I am sure that the males of ow field crickets rid themselves 

 of the spermatophore, if deprived of the females, only ex- 

 ceptionally. In all my many observations I have seen the thing 

 occur but three times, twice in Gryllus and once in Nemobius. 

 In every case it was rubbed off after an unsuccessful attempt 

 to introduce it into the female. In these trials the plate was, 

 no doubt, partially removed from its normal position in the 

 forming organs, because in most cases the males made no 

 effort to remove the spermatophore, although they had tried 

 to copulate. 



I have not seen that the males make any movements while 

 forming a spermatophore, but I would not positively deny that 

 they do so. I have frequently kept them under observation 

 for a few hours after copulation; some would form a new 

 sperm bearer and others not. One male copulated a second 

 time after a very short interval, but I did not watch him mean- 

 while. Some other specimens did not have the spermatophore 

 formed after hours of watching. 



The female carries the vesicle very frequently until she is 

 about to mate again. If this comes soon after a previous copu- 

 lation, she will remove the vesicle. She does this with her 

 mouth parts, bending the abdomen ventrally. She may place 

 herself partly on her back and holding the abdomen against 

 the ground force her mouth parts back so as to reach the 

 ampulla of the spermatophore. If the abdomen is too much 

 distended by eggs, she frequently rubs it off by dragging the 

 abdomen on the ground. The longer a spermatophore has been 

 carried by the female the easier it is removed. In only one 

 instance did I see a female mount upon a male with the sperm 

 bearer still in place. After a good many efforts the male suc- 

 ceeded in pushing the old spermatophore partially out of the 

 way and placing a new one. The female then carried both, 

 the old one apparently hanging on by one hook. 



The Spermatophore. 



Lespes says : "The spermatophore of the field cricket is com- 

 posed of a vesicle almost round, of a brown, more or less dark, 

 color. It terminates at one extremity by a whitish papilla 

 and is continued on the other end by a transparent plate, al- 



