74 The Marsupial Ovum, fyc, of Echidna hystrix. [Jan. 8, 



annular fossae during the period the mother suckles her progeny, 

 disappearing afterwards altogether. 



The examination of two male Echidna which I had an opportunity 

 to carry out during September led me to what I believe is another new 

 discovery. Respecting the mammary glands of Ornithorhynchus Pro- 

 fessor Owen ("Phil. Trans.," vol. 122, 1832) says :— " In the male both 

 Dr. Knox and Professor Meckel have been unable to detect these glands, 

 and after a careful scrutiny with the same view in a well preserved 

 specimen of that sex, I have not succeeded in detecting more than a 

 few minute lobules occupying a space of about four lines in situations 

 corresponding to those in the female, but the nature of which, from 

 the total absence of corresponding foramina on the external surface 

 of the integument, may still be doubted." 



Furthermore, in the " Zoological Record " for 1876 I read: — " 0. 

 Creighton suggests that the glandula femoralis, which opens by a 

 long duct on the spurs of the male in Ornithorhynchus and Echidna, 

 may prove to be the homologue of the mammary gland of the female." 

 " J. Anafc. Phys.," xi, pp. 29-31. 



This latter quotation of a certainly original suggestion shows that 

 up to the end of 1876 nothing could have been known about the 

 unmistakable homologue of the mammary gland of the female which 



1 recently discovered in two male Echidna, and I am not aware that 

 any new facts to elucidate this question have been published up to 

 the present time. 



I was, therefore, not a little surprised to find in the two male 

 Echidna I examined, in situations corresponding to those in the 

 female, similar tufts of short hair quite as plain as those indicative 

 of the mammary areolae in my female. On the animals being 

 skinned, I found without any difficulty rudimentary mammary glands. 

 In the largest of my two specimens the one mammary gland forms a 

 mass about 8 mm. long by 4 mm. wide, the lobules being about 



2 mm. long. The other gland is a little larger. The glands are 

 built after the same plan as the female glands, and contain a con- 

 siderable number of lobules. 



My anatomical preparations and the Echidna egg discovered by me 

 will remain in the Adelaide Museum. 



In conclusion, I should not forget to mention that I am aware of 

 Mr. W. H. Caldwell's discovery of the oviparity of the Monotremata, 

 made about the same time as it seems at which my discovery was 

 made, and that the British Association at their Montreal meeting 

 received the information of Mr. Caldwell's discovery about the same 

 date at which my Echidna egg was exhibited at a meeting of the 

 Royal Society of South Australia. But this is all I know at present 

 about Mr. Caldwell's discovery. 



