IIEPKODUOTIVE CYCLE JX DASYUliUS VIVEHKINUS. 135 
purposes of descriptiou, and the terminology employed is, with 
slight modification, tliat suggested by Heape ( 11 ). As the 
cestral cycle in Dasyurus differs considerably from that of the 
Eutherian mammal, it has been found necessary to introduce 
two new terms, viz. Post-oestrus, to designate the period 
which intervenes between oestrus and ovulation ; and Pseudo- 
pregnancy, to designate the period which, in the non- 
pregnant animal, follows ovulation, and in which the changes 
in the ovary, mammary glands and uteri are essentially 
similar to those in the pregnant female. 
We wish to express our thanks to Mr. F. Pittock, of the 
Zoological Department of this College, for invaluable help in 
the preparation of the photomicrographs on Plates 6-8. 
Matekial. 
The information relating to the breeding habits of the 
animal was obtained largely from the records mentioned 
above. These records relate to 170 females, which fall into 
two classes — pregnant and non-pregnant. Of the non-preg- 
nant females killed, 13 were prior to ovulation, 19 were after 
ovulation, and in 6 there was no record of ovulation. Of 
the pregnant animals, 37 had less than twent}^ embryos, 35 
had more than twenty embryos, in 25 there was no definite 
record of the number of embryos, and 35 were post-partum. 
Examples of individual records relating to these females 
have been given previously (20), and further examples are 
given later. 
For the purposes of the present paper, the uteri of sixteen 
females were cut in serial section in order to study the 
histological changes occurring therein. These uteri were, 
with two exceptions, from non-pregnant animals both before 
and after ovulation, and were fixed either in picro-corrosive- 
acetic acid, strong Flemming’s fluid, or in Hermann’s fluid, 
all of which gave very good fixation, Flemming’s fluid being 
particularly good for the cilia in the uterine glands. The 
sections (about 8 jn thick) were stained with h^ematoxylin 
