Uterine Ova o/" Echidna hvstrix. 375 



Haacke, Ph.D., records the fact that on the 25th Auo-ust 

 ill that year he found an egg " in the mammary pouch (not 

 the uterus) of a living Echidna hystrix, which he had received 

 about the 3rd of the same month from Kangaroo Island. The 

 t^g was unfortunately decomposed inside ; but the circum- 

 stance of the mother having been worried by being captured 

 and kept in captivity easily accounts for this. On Tuesday, 

 September 2nd, Dr. Haacke laid a number of specimens on the 

 table, including an egg found in the pouch of a female Echidna^ 

 in support of the theory that the Echidna, though a milk- 

 giving animal, lays eggs, which are hatched in the pouch." 



Since the foregoing paragraphs were in type, I have been 

 favoured with a letter (dated Sept. 16, 1884) from my friend 

 Dr. Bennett, F.L.S.,of Sydney, New South Wales, enclosing 

 the subjoined " cutting " from the ' Sydney Herald ' news- 

 paper : — 



^^ Embryology . 



^^To the Editor of the 'Herald: 



" Sir, — I send j^ou the following information, believing 

 that the fact will interest some of your readers. The embryo- 

 logy of the Monotremata Ornit]iorhynchxi.s and Echidna^ com- 

 monly known as platypus and porcupine, is, up to the present 

 time, absolutely unknown. Considering the unique structure 

 of these animals, it was probable that a knowledge of their 

 development would yield important results. This is the case 

 in a greater degree than I had anticipated. Both forms are 

 oviparous. The amount of food-yolk in the egg is very 

 large, and consequently there is only a partial segmentum 

 (meroblastic type). The Q.g^ is laid at an age equal to a 

 30-hour-old chick, and is enclosed in a strong, flexible, white 

 shell ; it measures about three fourths of an inch in the long 

 axis and half an inch in the short. 



'■'' Ornithorhynchus produces two such eggs at a birth, while 

 Echidna has only a single one. The former places her eggs 

 in the nest at the end of one of the burrows, the latter carries 

 her egg in a ventral pouch. I have already obtained most 

 of the stages in the development, and hope to get a sufficient 

 number during the present breeding-season. I take this 

 opportunity of asking your readers to help me to get a larger 

 number of the embryos of marsupial animals than 1 at present 

 possess. Since my arrival last October I have collected many 



29* 



