52 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



VOL. xxvni. 



the eggs are all deposited the sacculus becomes very small. Some- 

 times it is wanting, but the annulate tubes are present and connect 

 direct to the ovary. The significance of these organs is not fully 



known, l)ut the sacculus contains sper- 

 matocysts which are supposed to reach 

 it through the annulate tubes. 



Some, if not all, of the Gamasidiij 

 have a most remarkable method of 

 coition, which Michael has discovered 

 and described in detail. The male, 

 which is commonly a little smaller 

 than the female, clasps the latter by 

 the legs of one side and crawls under 

 her. His abdomen extends back be- 

 yond that of the female, and he grasps 

 her l)v his legs. Then a clear sac 

 emerges from the genital aperture of 

 the male, gradually enlurglng until 

 it is of full size and shape, which is 

 constant for each species. Usually 

 this sac or bubble is flask-shaped, 

 with a long 

 n e c k . It 

 incloses the 

 spermatozoa floating in a clear viscid liquid 

 (sometimes within spermatocysts). The 

 male clasps this bubble with his mandibles, 

 which are often modifled apparently for 

 such' purpose. The male then applies the 

 small end of the bublfle to the vulva of the 

 female, often inserting his mandibles for 

 some distance. Here the sural I end of the 

 bub})le bursts and the liquid and sperma 

 tozoa are discharged into the spermatheca 

 of the female. The Jjubble is rather Arm, 

 and when empty does not collapse, })ut 

 shriidvs somewhat. After the male leaves 

 the female he proceeds to clean his mandi- 

 bles. In those species in which the female 

 has no spermatheca, l)ut has annulate tubes 

 connecting to the acetabula of the third FiG.gi.-DERMANYssus galling, i^, 

 pair of legs, it is probable that the bubble ^^^^^^^^' '«• ^^ak; v, anal 



, . PLATE. 



IS applied to these apertures, and not to the 



vulva. The spermatozoa thus passing into the sacculus fcemineus, 



from which they may pass into the ovary as occasion demands. In 



Fig. 9U.— Dekmanyssus galling. 



