213 



June 28, 1859. 



Dr. Gray, F.R.S., V.P., in the Chair. 



The following papers were read : — 



1. Notes on the Duck-bill (Ornithorhynchus anatinus). 

 By Dr. George Bennett, F.Z.S. 



(Mammalia, PI. LXXI.) 



On the morning of the 14th of September, 1848, I received 

 through the kindness of Henry Brooks, Esq., of Penrith, six speci- 

 mens of the Ornithorhynchus — an unusually large number to be 

 captured and sent at one time — consisting of four full-grown males 

 and two full-grown females. As usual, the latter were much smaller 

 in size than the former. Some of these animals had been shot, 

 and others captured in nets at night, at a place named Robe's Creek, 

 near the South Creek, Penrith, about thirty miles from Sydney. 

 They were all in good and fresh condition, excepting one of the fe- 

 males, in which some degree of decomposition had taken place, but 

 not sufficient to prevent examination. On dissection, I found the 

 uteri of the females (although it was the commencement of the 

 breeding season) unimpregnated ; but in the four males the testes were 

 all enlarged, resembling pigeons' eggs in size, and of a pure white 

 colour. At other seasons of the year I have observed them in these 

 animals not larger than a small pea, and this being the commence- 

 ment of the breeding season could alone account for their size ; so 

 that they show in this respect a great resemblance to what is observed 

 in most birds during the breeding season of the year. I am not 

 aware of this peculiarity existing in any other Mammalia. The testes 

 in all the specimens were of equal size, and measured If inch in length 

 and 1 inch in the diameter. I preserved one animal with the testes 

 in situ, and detached the testes from the others, placing them in 

 spirits for a further examination if required. 



On examining the cartilaginous lips of these animals as they were 

 lying heaped upon the table, dripping wet as if just emerged from 

 the water, they were dark grey above, and mottled of a darker or 

 lighter colour underneath, as is shown in the drawing made from life 

 by G. F. Angas, Esq. (PI. LXXI.), and which I have not yet s,een 

 correctly represented in any coloured drawing or engraving of the 

 animal, in consequence of their not being taken from a living or 

 recently dead animal. Over the eye is a tawny brownish-yellow spot, 

 which marks distinctly the situation of that minute but brilliant 

 organ of vision. These animals have horny teeth on the tongue. 

 On the back part of this organ there is a bulb which serves to pre- 

 vent the passage of the food collected in the mouth together with 



