308 ME. A. D. MICHAEL ON THE 



not only with the Dermaleichi, but also with all other families of 

 Acarina ; and in his treatise on the Gfamasinae before quoted he 

 says (at p. 322) : — " Copulation in the Gramasime, as in all Acarina 

 which we have observed, does not take place by the vulva of ovi- 

 position, which does not exist at the time of copulation, but by 

 the anus. It is not the large, adult, egg-bearing female which 

 receives the male, but the young female, still bearing the appear- 

 ance of a nymph, and not presenting any trace of sexual organs. 

 It is only after fecundation, and after a final change of skin, that 

 the oviscapte, or vulva of deposition, appears." 



I have elsewhere given my reasons for being decidedly of opi- 

 nion that in the genus Glyciphagus, at all events, copulation takes 

 place with the adult female ; and I have now to add that the 

 result of my observations on the Gramasinse leads me to the con- 

 clusion that in those species which I have bred copulation has 

 taken place with the adult female, and not with the female in any 

 immature stage ; and, in my opinion, Megnin is not correct in 

 saying that in the Gamasinae it takes place by the anus. 



I was desirous of seeing how the copulation took place, and 

 particularly how the enlarged second pair of legs of the male in 

 such species as crassipes were used. When my captives got 

 accustomed to the cells, I had several opportunities of watching 

 it. The adult male rushed up to the adult female (never, in any 

 instance that I saw, to an immature one), approaching her from 

 behind ; on reaching her, he turned suddenly over on his back 

 and slipped underneath the female, seized one of her hind legs 

 with each of his enlarged legs of the second pair, which was 

 doubled back upon itself. The leg of the female was clasped 

 between the great apophysis on the second joint of the enlarged 

 leg of the male, which curves forward and upward, and the smaller 

 one on the fourth joint, which in this position of the leg curves 

 backward and downward ; this arrangement brings the genital 

 aperture of the male immediately below the vulva of the female, 

 which is placed further back than the male organ. The two are 

 so firmly locked, that they may sometimes be rolled over and 

 examined without separating. 



Conclusions. 



The principal results of my observations may, in my opinion, 

 be shortly summarized as follows : — 



1. That Megnin is correct in saying that Gamasus coleoptra- 

 orum, and other allied creatures with the conspicuously divided 



