REPKODUCTIVE CYCLE IN DASYLIRUS VIVERRINUS. 167 
flow. This latter we regard as the morphological and })hysio- 
logical equivalent of the degenerated epithelial elements and 
blood extravasations met with in the pseudo-pregnant uterus 
of the marsupial.^ We are therefore in complete agreement 
with those writers (Van Herwerden (12), Grosser (7), 
Hitschmann and Adler (15), Beard (3) and others) who hold 
that menstruation ... is the expression of chang’es in 
the uterine mucous membrane which are associated with 
preparations for the reception of a fertilised ovum,^^ and 
that menstruation itself is only a secondary process — a de- 
generation of the mucous membrane which from a failure of 
pregnancy has not been able to fulfil its purpose (Grosser, 
loc. cit., pp. 97 and 102). 
Our observations afford no support for the view that “men- 
struation is identical with ^ heaV ’’ (Heape (11) p. 59), nor 
for the view “ that menstruation in the Primates is the 
physiological horaologue of the pro-oestrum in the lower 
mammalia (Marshall (18) p. 162). 
As is generally recognised, menstruation is simply the 
outcome of degenerative uterine changes, and although 
these are manifested at the end of the pro-oestral period in 
Eutheria, our observations demonstrate that in the mursupial, 
they succeed both oestrus and ovulation, and cannot there- 
fore be considered as forming any part of the pro-oestral 
phase. 
Now, bearing in mind the lowly position which the 
Marsupials occupy in the mammalian series, and taking into 
^ Wiltshire states (27, p. 397), on the authority of Bartlett, that in 
kangaroos in the gardens of the Zoological Society, “ a mattery, slimy ” 
discharge from the cloaca, slightly tinged with a reddish colour, had 
been observed by the keeper in females at the time of “ heat.” We 
have one record of the occurrence of an apparently corresponding dis- 
charge from the cloacal aperture in Dasyurus. The discharge is 
described in our notes as “ a whitish glairy secretion, consisting of 
refractive granules, round and angular,” and is regarded as the secretion 
of the cloacal glands. We are not inclined to attach any importance 
to its occurrence in the present connection, but it is quite possible that 
the cloacal glands may become more active during prooestrus. 
