3.08 MR. F. K, BEDDARD ON HAPALEMUR GRISEUS. [June 3, 



in appearance from the surrounding mucous membrane of the uro- 

 genital canal. On either side of the colliculus seminalis and some- 

 what beneath is a comparatively large oval aperture, which appears to 

 be single, and communicates with the vas deferens and vesicula semi- 

 nalis of its own side. By passing a fine bristle down the vas deferens 

 from above, it was ascertained that the latter in reality is distinct from 

 the duct of the vesicula seminalis, and runs along its inner wall as a fine 

 tube, the external orifice being placed to the inside of that of the 

 vesicula seminalis and only separated from it by the thickness of its 

 own wall. 



In the majority of Lemurs the vas deferens opens separately from 

 the vesicula seminalis and to the inside of it. In Lemur catta the 

 orifices of both are situated on the upper surface of the colliculus 

 seminalis ; the vas deferens opens on to a small tongue-shaped 

 process, which projects into the inner side of tlie crescentic aperture 

 of the vesicula seminalis which nearly surrounds it. In Loris 

 gracilis, Nycticehus tardigradus, and Perodicticus the orifices of the 

 vasa deferentia and vesicnlse seniinales, althougli very close together, 

 open separately. Prof. Huxley states oi Arctocebus : — -"The vasa 

 deferentia terminate in the urethra by two apertures placed close 

 together, upon the end, or rather the under surface, of a papilla-like 

 colliculus seminalis, which is slightly bifid at its extremity. At first 

 I took the notch which causes tliis appearance for the mouth of an 

 uterus masculinus, which I imagined might lie on the elevated ridge 

 which extends between the apertures of the vasa deferentia and those 

 of the ureters ; but caret"ul examination did not reveal the existence 

 of any such structure. Two longitudinal folds of mucous membrane, 

 along which the apertures of the prostatic ducts are situated, extend 

 from the colliculus and form the lateral boundaries of a wide fossa, 

 which it overhangs. This fossa receives at its up[)er and back part 

 the ducts of two large oval sacs, which are perfectly distinct from 

 one anotiier, though their inner walls are united for some distance. 

 The walls of these sacs are raised into oblique folds, and they lie at 

 the back of the neck of the bladder behind the vasa deferentia, and 

 occupy tiie place of the vesiculce seminales. As they do not 

 communicate directly with the vasa deferentia, however, I am 

 doubtful whether they ought to be considered as representing the 

 vesiculee seminales, or as a large uterus masculinus." 



In Avahis laniger, Milne-Edwards figures and describes the 

 vesiculse seminales as opening a long way behind the vasa deferentia ; 

 while in Propithecus the same author states that the vesicula 

 seminalis opens, together with the vas deferens of its own side, by a 

 common aperture. 



There is therefore a considerable difference in different Lemurs 

 between the relative positions of the apertures of the vesiculse 

 seminales and vasa deferentia. Avahis laniger is at one extreme of 

 the series and Arctocebus at the other; in this latter genus the 

 disappearance of the posterior portion of the colliculus seminalis has 

 caused the apertures of the vesiculae seminales to unite below the 

 apertures of the vasa delerentia. In all other species that 1 have 



