148 
J. H. HILL AND CtlAS. H. o’dONOGHUE. 
Ovulation may be sueceeded by one of two states. On the 
one hand, if the ova be fertilised, there follows a period of 
pregnancy, which in its turn is succeeded by a nursing 
period. On the other hand, in the absence of copulation or 
fertilisation, there follows an interval in which the various 
organs undergo a series of marked alterations, essentially of 
the same nature as those normally undergone in the pregnant 
and post-partum female. To this period, therefore, we pro- 
pose to give the name of pseudo -pregnancy 
Pregnancy. 
If fei-tilisation is effected, ovulation is normally succeeded 
pregnancy. The ova are fertilised in the upper parts of 
the Fallopian tubes, and the second polar body is there given 
off. They pass down the tubes, apparently with considerable 
rapidity, into the uteri, where cleavage begins (Hill (14) ). 
We have already directed attention to the fact that there 
is no correlation between the number of ova shed during 
ovulation and the accommodation available in the pouch 
(Hill (14) ), the number of ova shed at one period being, as a 
rule, far in excess of the normal number of teats (six). Our 
records show that out of seventy-two pregnant females in 
which there is a definite record of the number of eggs or 
embryos, thirty-five had more than twenty, and the remaining 
thirty-seven less than twenty. Moreover, whilst amongst the 
thirty-five one had as many as thirty-five vesicles, in only 
three of the remaining thirty-seven were there less than six 
embryos, and in one of these only one uterus was pregnant. 
Although a proportion of the eggs may for one reason or 
other fail to develop normally, it would appear to happen 
generally that a larger number of young are cborn than can 
possibly survive, the pouch accommodation being' strictly 
limited. Our records afford two specific instances of females 
which were examined shortly after parturition. In one of 
these, eighteen young were found, of which eleven occurred 
adhering to the hairs round and directly below the opening of 
the pouch, six were attached one to each nipple, and one 
