BAUMGARTNER: COPULATION IN GRYLLID^. 337 



the forming organ, that is, in the stylet of the armature, until 

 given off to the female." 



This description is somewhat indefinite because of the un- 

 certain meaning of the phrase "genital armature." Besides, 

 the application of the words "in front" and "behind" is not 

 certain. I do not believe that the differences between Lespes's 

 description and my observations can be accounted for by sup- 

 posing such differences exist in the different species studied. 

 Both of us used Grylhis domesticus some, and as shown below 

 we found only small minor differences between the house 

 cricket and our own species of field crickets. 



Before discussing the formation of this peculiar spermato- 

 phore farther let me state as clearly as possible the mechanical 

 problem involved. There is a mold made up of a system of 

 bracing rods of chitinous material and a thin fibro-muscular 

 membrane. Into this mold leads a single tube, which has to 

 bring the sperm and the secreted fluid for the covering. The 

 ampullar part of the finished spermatophore has apparently 

 a double wall, and so there may possibly be two kinds of secre- 

 tions, although a careful study of the gland shown in figure 10 

 makes me doubt it. The question is, then : How are the sperm 

 kept separate, and especially how are they held in the center 

 while the soft liquid is poured around them and hardens? If 

 there is a second layer in the wall the incomplete ampulla would 

 have to be held in the center while the second inflow and hard- 

 ening occurs. To place a semifluid substance within another 

 fluid substance and hold the former at the center while the 

 latter hardens would be a difficult feat for any mechanic. 

 I do not see how the apparatus provided is sufficient to ac- 

 complish the result. Yet I have seen so many well-formed 

 spermatophores that there can be no doubt of the end product. 



The way to solve the problem readily suggests itself. One 

 needs to get a lot of specimens showing the various stages in 

 the formation of the vesicle. Such a series of stages I have 

 been hoping to get, but have thus far not succeeded. In all 

 my many dissections I have never found a partially formed 

 vesicle. It is hardly feasible to follow the process in a living 

 specimen, as the attempts to make observations would interfere 

 with the normal formation. 



Although I am not able to give a description of the exact 

 method of formation, I shall nevertheless make some sugges- 



2-Univ. Sci. Bull., Vol. V, No. 19. 



