122 Rote on the Reproduction of the Omithorhynchus. 



glands were very large, as in the last. I examined the 

 opened burrow two days afterwards. The entrance was at 

 the root of a tree, on the margin of a permanent water-hole. 

 It extended up the bank, which at its extremity was about 

 eight or ten feet high, following the contour of the ground, 

 at a uniform depth of from eighteen inches to two feet, the 

 total length being twenty feet. The nest, which must have 

 been of large size, was composed of small gum-leaves and 

 grass. 



The unimpregnated female was sent from Hazelwood, in 

 Gippsland, by Mr. E. Keighly. It was sixteen inches long, 

 slender, the fur on the abdomen of a beautiful silvery grey, 

 with a reddish-brown streak in the centre. The ovaries 

 were small, granular, and contained no ripe ova. The 

 mammary glands were very small, of a reddish colour, the 

 lobes fleshy. 



It has been recently announced that Mr. Caldwell, who 

 has been investigating the reproduction of the Monotremata 

 and Ceratodus in Queensland, has ascertained that the 

 Omithorhynchus is oviparous, and that the ova are mero- 

 blastic. The full report of his researches is anxiously looked 

 for, and will be received with the greatest interest by all 

 biologists. In the meantime, all that is certainly known is 

 that ova of the size of those now shown have been found in 

 the uterus, that young of one and a half to two inches in 

 length and upwards have been found in the nest, and that 

 these are suckled by the mother. The intermediate stages 

 of their development are absolutely unknown. It is to be 

 hoped that Mr. Caldwell has been able to clear up the early 

 life history of these extraordinary creatures, the mystery 

 shrouding which, we must all confess, is not very creditable 

 to Australian naturalists and observers. 



