402 PROCEEDINGS OF SECTION D. 



my notice is one by Dr. E, C. Hobson, in the Tasmanian 

 Journal of Natural Science, kc. for ] 842. The pubhcation 

 appears to be a rare one, and I am indebted to the Rev. W. 

 Colenso, F.R.S., for the loan of what I beUeve to be the 

 only copy in this colony. Dr. Hobson's paper contains 

 several interesting observations, although his morphological 

 knowledge is of the slenderest. 



In a full-grown male Caller hynchus, 75 cm. long, the 

 vesicula seminalis is a dilatation of the vas deferens, about 

 12 cm. in length and 16mm. in diameter. It lies immediately 

 ventrad of the kidney and epididymis, its anterior end being 

 just mesiad of the posterior end of the testis. Anteriorly it 

 communicates with the vas deferens, posteriorly it opens by 

 a short narrow tube into the urinogenital sinus. It has a 

 deHcate sea-green colour, and the septa and spermatophores 

 presently to be described can be seen through its thin walls. 



A longitudinal section shows that the mucous membrane 

 of the vesicula is produced into extremely delicate transverse 

 septa, about 1 mm. apart, which divide the cavity of the 

 organ into regularly arranged compartments. The septa 

 are, however, not complete : towards one side of the vesicula 

 seminahs they are interrupted so as to give rise to a narrow 

 longitudinal canal along the whole length of the organ. 



The entire cavity of the vesicula is filled with a clear pale 

 green jelly of moderate consistence, which dissolves in water 

 with much frothing, and hardens in alcohol without loss of 

 colour or transparency. In this are embedded the sperma- 

 tophores, globular or ovoid semi-opaque bodies, about 1 mm. 

 in diameter, arranged in layers separated by the septa, but 

 crowded together in the longitudinal canal mentioned above. 

 Pressure upon the vesicula forces a small quantity of jelly 

 with contained spermatophores from the canal into the urino- 

 genital sinus. 



Spermatophores also occur in the vas deferens and in the 

 tubules of the posterior half of the epididymis, while the 

 anterior portion of the latter contains free sperms. This is 

 well seen by snipping oft' a piece of a tubule of the epidi- 

 dymus and squeezing out its contents on a slide : if taken 

 from the anterior part of the organ a granular substance 

 exudes, if from the posterior part fully formed sperma- 

 tophores. In the specimens examined the only sperms which 

 exhibited movement were some that had made their way 

 into the urinogenital sinus. 



The spermatophores are invested with a dehcate membrane 



