( 1080 ) 
to become personally acquainted with his early blastocysts of Dasyurus 
among which, as he distinctly mentions, in addition to the one 
figured in fig. 37 he has come across vet more “abnormals.” Three 
ot these “abnormals” are here figured and are seen to contain 
proliferating cells. Their aspect in many respects resembling that of 
SuLenKa’s Pl. 17 fig. 11 and Pl. 18 fig. 2, on which my own inter- 
pretation, differing slightly from that of SELENKA was based. 
From the figures here given, magnified about 150 times and 
obtained from consecutive sections of one blastocyst each, anybody 
may make plastic reconstructions in space. It can then not be denied 
that some of these blastocysts do contain an inner cell mass which 
in the case of fig. 1 to 5 was of the utmost regularity and composed 
of 16 cells. In most cases this mass is adherent at one spot to the 
trophoblast, as we notice it in Kutheria. It moreover strikes us that 
in fig. 1—4 the 16 cells seem to be imbedded in a sort of matrix, 
distinctly the same as is present in the preparation from which Hite 
has taken his fig. 87 and which he has there termed cy/, whereas 
in that case (of which I also give illustrations in fig. 7a—d) the one 
cell enclosed inside the blastoeyst and designated by Hitt by the 
letters abn (standing for abnormal) is vet single in contradistinction 
to the 16 cell stage just now described and figured. This one cell 
is not imbedded in, but in close contact with the mass cy/. 1 do 
not wish for the present to give a further description or interpretation 
of this matrix, which Hin. designates as coayu/um and which is also 
found in those blastocysts which he regards as normal and in which 
there is no cellproliferation inside the blastocyst-wall. 
I cannot convince myself that the histological aspect of the enclosed 
cells would justify anyone to stigmatize them as “abnormal”. 
However, from the evidence at present available I am not going 
to conclude that, contrary to Hinn’s conviction, the blastocyst here 
figured are normal and that those which he regards as normal — and 
which though lacking any internal cell mass are more numerous — 
should be looked upon as abnormal. 1 am only pretending that a 
decision on this head is for the present moment premature, and that 
we must necessarily postpone its.definite solution until the examination 
of a much larger batch of blastocysts of either Dasyurus or Didelphys 
has furnished us with a key to this riddle *). 
1) [ may here remark that an attempt may be made to explain away the diffi- 
culties against a direct comparison between the “normal” and the “abnormal” 
blastocysts in assuming that in many cases of Dasyurus the embryonal knob cells 
arrange themselves in a flat layer without ever being overgrown by the unilaminar 
trophoblast wall (such as is also the case in all the reptiles and birds as far as 
