BAUMGARTNER: COPULATION IN GRYLLID^. 343 



very abundant in the greenhouses. The male has no chirping- 

 organs and so the courting is all done by means of the long 

 antennae. The female mounts on the back of the male, when 

 he hooks an almost spherical ampulla full of sperm into her 

 vagina. During the latter act a viscid fluid flows out on either 

 side and forms two somewhat irregular roundish masses larger 

 than the original ampulla, which now lies between the two. 

 Sometimes the female began immediately after copulation to 

 eat this substance, doing it more readily if the couple was dis- 

 turbed. 



As to a use or meaning for this outflow of fluid and its sub- 

 sequent hardening it is difficult to suggest a satisfactory one. 

 Of its regular occurrence there can be no doubt, as I observed 

 it many times in Diastremmena and once in Gryllotalpa. It 

 may function as an additional fastener to hold the apparatus in 

 the vagina. Yet this seems hardly necessary, as the spermato- 

 phore apparently remains in place before it is hardened. It 

 may have something to do with the emptying of the vesicle, 

 contracting around the ampulla, thus forcing out the sperm. 

 Or it may be concerned with the removal of the spermato- 

 phore from the vagina, acting as a bait for the female to re- 

 move it. 



SUMMARY. 



1. The reproductive apparatus of Gryllus is not of the 

 simplest type, as was reported by the earlier investigators and 

 as is still suggested by our textbooks. These organs are rather 

 of the most complex kind found among the insects. They were 

 studied and described with a good deal of detail, and the cor- 

 rect method of the transfer of the spermatozoa was indicated 

 by Lespes in 1855 ; but the work was discredited and neglected. 



2. The male carries the sperm to the female in a special 

 structure, the spermatophore, formed by the secretion of the 

 glands annexed to the common duct. 



3. The essentials of the spermatophore, as shown by the 

 study of several genera of Gryllidse, are a hollow vesicle to act 

 as a retainer, and a hollow thread-like tube which carries the 

 sperm into the spermatheca of the female. To the tube are 

 added some enlargements which serve to hold the structure in 

 the vagina. 



4. The so-called genital armature of the male crickets con- 

 sists of a mold for forming the spermatophore and an appa- 

 ratus to transfer the same to the female. 



