498 MR. F, E, BEDDARD ON THE [ Apr. 27, 
the exception of the last-named, Petawrus taguanoides. In that 
species he found that the postcava lay to the right ‘‘as in the 
Cat.” My own observations quite bear out those-of Hochstetter, 
to whose list Iam able to add a few species dissected by myself 
which that anatomist had not the opportunity of examining. 
Tt have never met with the condition which characterises Petawrus 
taguanoides in any Marsupial. 
In addition to these types, McClure, as has already been 
mentioned, has dissected many examples of Didelphys marsupialis, 
as well as the Wombat and Petrogale sp.*, while Parsons has 
reported upen Petrogale xanthopust, and Parsons and Windle 
upon JJacropus rufust. The figure of Petrogale given by 
McClare$ quite agrees with that of Macropus bennetti illustrating 
Hochstetter’s remarks ||, In neither of these figures is the 
anterior spermatic veins represented, though McClure states that 
they are present, as also in the Wombat. They are furthermore 
represented by the last-mentioned anatomist in Didelphys4, and 
the anastomosis between the anterior and posterior spermatic 
veins clearly shown. Inasmuch as McClure has remarked that 
in the Wombat the spermatic veins also open in the neighbourhood 
of the kidneys, as well as into the postcaval trunk, I do not quite 
understand his saying, in a later paper, that “In a number of 
adult Australian Marsupials, however, the spermatics do not open 
into the postcava, as in Didelphys, but open into it at the base 
of the renal veins, as in Phascolomys wombat, or into the renal 
veins themselves, as in Votoryctes typhlops,” as observed by Miss 
Sweet**. It would appear, however, that McClure does not allow 
the value of a spermatic vein to a vessel often slender which does 
pass between the gonads and the renal vein; for he writes 
thus of Didelphys: ‘In none of the adults examined did the 
spermatics open into the renals, although an anastomosis between 
the latter and the spermatics was invariably TY present, on each 
side, in the form of a small vein which followed the ureter.” As 
a matter of fact, I have myself generally found two such small 
veins which were frequently large veins fully as important as 
what I term the posterior spermatic veins, which open behind 
them into the postcaval itself. Nor, indeed, is any difference of 
size shown by McClure in the plate{{ which illustrates the main 
venous trunks (as well as the arterial) of Didelphys virginiana. 
In a female Zrichosurus vulpecula 1 found that the postcaval 
and its various branches were arranged as follows :—The asym- 
metrical renal veins not only lacked symmetry in their plan of 
opening into the postcaval trunk, but also in their number, for 
* Amer. Journ. Anat. vol. ii. 1903, p. 388. + P. Z. S. 1896, p. 683. 
~ J. Anat. Phys. vol. xxxii. 1898, p.119. This paper deals mostly with osteology, 
muscles, and viscera. But the authors mention the ventral position of postcaval. 
§ Loe. cit. p. 388, fig. v1. || Loe. cit. p. 626, fig. 13. 
@ Amer. Journ. Anat. vol. v. 1906, p. 199. 
** Proc. Roy. Soc. Victoria, vol. xvii. 1904, pt. 1. 
++ Italics Dr. McClure’s. 
te Amer. Journ. Anat. vol. v. 1906, pl. i. 
