72 



Dr. W. Haacke. The Marsupial Ovum, the [Jan. 8, 



ordinary fermentative fibrin formation, that fibrin may be deposited 

 from blood by simple physical means, without any ferment process ; 

 for this new substance becomes, as I have stated, true fibrin, and yet 

 the plasma does not contain ferment. Possibly this mode of fibrin 

 formation is of importance in the formation of a thrombus. 



The peculiar microscopical characters should also be noted, as 

 possibly affording an explanation of the observations made by Osier, 

 Bizzozero, Hayem, and others. I refer of course to the granules, Blut- 

 plattchen, hsematoblasts, described by these authors. 



As I am actively engaged on this subject, and as I hope before long 

 to produce a complete account of my researches on the coagulation of 

 the blood, I have purposely confined myself to the briefest outlines. 



VI. On the Marsupial Ovum, the Mammary Pouch, and the 

 Male Milk Glands of Echidna hystrix." By WlLHELM 

 Haacke, Ph.D., Museum Director to the Public Library, 

 Museum, and Art Gallery of South Australia, Adelaide, 

 and late Assistant Director to the Zoological Institute, 

 Jena. Communicated by the President. Received Novem- 

 ber 12, 1884. 



On the 3rd of August, 1884, a number of living specimens of 

 Echidna hystrix were brought to Adelaide from Kangaroo Island, 

 where they had been captured some days previously. I was unable 

 to procure more of them than two, a male and a female, as the others 

 had been disposed of before I heard of them. But those two 

 afforded me the good fortune of making a discovery that, in our 

 days, perhaps no naturalist would have expected to make. I found 

 an egg in the mammary pouch of the female, and was thus enabled 

 to prove that Echidna is really an oviparous mammal. 



This discovery was made on the 25th of August ; it was announced, 

 and the egg was exhibited at the meeting of the Royal Society of 

 South Australia on the 2nd of September ; the scientific society 

 referred to being the first one on record, the members of which had 

 an opportunity of examining an egg laid by one of the Monotremata. 



On September 14th I killed and dissected the female Echidna that 

 had laid the egg. Neither the pouch nor the oviducts nor the uterus 

 contained any more ova, but all the female organs were well developed. 

 Only the right ovary contained what evidently was a corpus luteum, 

 but there was only one. This corpus luteum deserved its name, as it 

 was orange coloured instead of having a pale fleshy tint as is the 

 case with the ovisacs still containing undeveloped ovula ; it was not 

 quite so large and round as the largest of the ovisacs. 



