Art. XV. — Note on the Reproduction of the 

 Ornithorhynchus. 



By P. H. MacGillivray, M.A., M.R.C.S., F.L.S, President 

 of the Bendigo School of Mines Science Society. 



[Read 20th November, 1884.] 



The Bendigo Science Society having offered a reward for 

 female specimens of Ornithorhynchus, procured in the end of 

 October or beginning of November, several have been for- 

 warded, a brief notice of the examination of which may be 

 of interest. The specimens were five in number. Of these, 

 two contained ova, two had given birth to the young or ova^ 

 and one was unimpregnated. 



Of the first specimen I received only the left uterus and 

 ovary, which had been removed and were sent to me by Mr. 

 Long, of Elmore. It was shot on 1st October. In the 

 ovary I found two ruptured ovisacs. One was much pro- 

 jecting, with a conical or mamilliform point, at the summit 

 of which was a transverse rupture. It was bright red, the 

 colour deepest at the apex. The other was not nearly so 

 prominent, of a yellow colour, the opening at the apex 

 nearly circular. In both, the edges of the openings were 

 everted. The walls of the uterus were very thick, and the 

 uterine glands were very distinct. The cavity contained a 

 considerable quantity of mucus. Two ova were found in it. 

 They were five millimetres in diameter, white, the envelope 

 tough and smooth. The contents could be seen to be fluid, 

 with a dense white mass occupying about a fourth part at 

 one side. One was situated in' the upper part of the uterus, 

 and was slightly adherent at two points to the lining mem- 

 brane, which it dragged with it when moved. When sepa- 

 rated some minute filiform shreds remained projecting from 

 its surface. The uterus at this part was very vascular, 

 tinged red, but there was no vascular connection, and the 

 adhesion seemed to be caused by some accidental inflam- 

 matory action. The other ovum was situated in a pouch or 



