368 A. A. W. HUBRECHT. 
paratory to the apposition of the allantois and yolk-sac, and to 
the formation of the placenta, as were above described for 
other mammals, we will then have to distinguish in this 
mammal a trophocalyx, as in the bat, and not a trophosphere, 
as in the hedgehog and the Primates, preceding the formation 
of the discoidal placenta. 
The last author to whom I wish to pay a passing tribute, 
although his contributions to the subject have appeared more 
than ten years ago, is Ercolani. I feel the more prompted 
to do so as neither Fleischmann (I. c., p. 71) nor Frommel (l.c., 
p. 39) appear to me to do justice to the very painstaking and 
extensive labours of this author, whose efforts would have 
found better appreciation if he had published his researches in 
a German periodical and not in an Italian academical quarto. 
We ought not to forget that his researches date from a period 
when the technical difficulties were much less easily overcome 
than nowadays, and that this fact reflects on his figures. 
Still, his pl. xi, fig. 2, in which details of the placentation of 
Vespertilio murinus are given, will stand a comparison 
with Frommel’s. 
For myself, Iam inclined to think that part of the opposition 
to some of Ercolani’s views is due to his having called the 
enormous and important proliferation of the stroma of the 
mucosa, preceding the fixation of the blastocyst in many 
mammals, a “ neoformazione glandolare,”’ whereas in the same 
treatise he has constantly insisted upon the fact that the 
glands of the uterus play no part in the phenomena of placen- 
tation. This nomenclature is not a happy one, and has cer- 
tainly been misunderstood more than once. And still it is a 
fact that in many mammalia an undeniable and rapid neo- 
formation of decidual tissue takes place before the blastocyst 
is in any way adherent to the uterine walls. The hedgehog 
offers a most striking example of this. And it was Ercolani 
who called special attention to this general fact.' This we 
should recognise even if we may differ from him in special 
1 T note with satisfaction, after completion of this MS., that Sedgwick 
Minot (‘ Journal of Morphology,’ ii, 3, pp. 378 and 430) shares in my appre- 
