1052 
PROFESSOR OWEN ON THE OYA OF THE ECHIDNA HYSTRIX. 
In a letter from Mr. G. F. Bennett, dated Toowoomba, January 14tli, 1879, he 
writes “ I was not able to get any more specimens this last season, but I hope to 
begin where I left off last year, and continue to the time advised in the letter of my 
father’s—that is, to the middle of September ; and then I hope I shall be able to give 
you material to decide this important question.” 
In February last I was favoured by receiving from Dr. Bennett, who had returned 
to Sydney, New South Wales, a letter of the date December 26th, 1879, in which 
I had the pleasure to read :—“ I have now sent you a case containing a tin of prepa¬ 
rations in spirit of the uteri of Echidna. I selected those I thought would interest 
yon, but I fear none of them yet solve the problem. One (not sent) I have ventured 
to open—distended uterus of one captured in August—and it contained a small semi¬ 
opaque ovum. Those sent were captured from August 30th to October 10th. One, 
taken September 24th, was not impregnated, but a young one was found in the 
pouch, and another on the 29th September.” 
I welcomed this satisfactory confirmation of the marsupial structure described in 
the paper of March 2nd, 1865,'“ and was gratified shortly after by receiving the “tin” 
of specimens notified as despatched by my friendly correspondent. 
The specimens, four in number, of the hinder half of the trunk and hind limbs, with 
the generative organs entire and in situ, were in a good state of preservation ; and my 
first leisure was devoted to their examination. In two of these the uteri were 
unimpregnated. In a third specimen, from a female killed August 30th, 1879, three 
ova were lodged in the deep folds of the thick and soft inner membrane or tissue of 
the left uterus (Plate 39, fig. 1, c ). There was no ovum in the right uterus (ibid., 
fig. 1, d,c). 
The ova were of a spherical form, and of different sizes ; the smallest had a diameter 
of 2ij millims., the next in size of 4 millims., the largest of G millims. 
The smallest ovum was situated nearest the vaginal end of the uterus, the next in 
size was nearer the Fallopian end, the largest held an intermediate position. Each 
was lodged in a smooth depression of the soft and thick inner uterine coat, and some 
threads of mucus extended over the larger ovum. These were shown by microscopical 
investigation not to be vessels, but filamentary portions of uterine secretion (fig. 2, a a), 
coagulated probably by the preserving fluid. A magnified view of the ovum, as seen 
undisturbed in its nidus, c', is given in fig. 2. 
In the fourth specimen, from a female killed on the 14th September, 1879, there 
was no ovum in the left uterus (ibid., fig. 3, c, ci) ; but in the right uterus (ibid., 
fig. 3, c, d) w r as an ovum of the size of the largest of the three in that of the date 
August 30th. It is shown in situ, with half of the smooth cell from which it was 
dislodged in reflecting the portion of the uterine wall, c, including the ovum with the 
other half of the cell. This was situated near the Fallopian end of the uterus. The 
parts being dissected while under colourless dilute alcohol, a slight touch of a camel’s 
* Phil. Trans., 1865, p. 671, Plate 39. 
