


REVIEWS. 153 
disturbed, and an anomalism is always produced, which manifests itself in 
the form of the blastoderm at first, and then in that of the vascular area. 
In fact, under these unusual esie the kenne of the cicatrix 
in ulm 
at, n 
in the opposite region. On this account (Il en résulte qui) the blasto- 
derm at first, and then the vascular area assumes an elliptical form, and 
the embryo is produced in one of the foci of the ellipse; while in its nor- 
malstate the embryo occupies the centre of a perfectly circular blasto- 
erm and vascular area. This result is very distinct, so distinct that 
allowing for the primitive dps (^Torenatin" of the embryo, 
and giving to the egg a certain position with respect to the source of 
heat, this excess of develo of a part of uie tikino may 
opm 
directed where it is desirable, peni to the left or the right of the embryo, 
either above its head or at its caudal extremity." 
*"The embryos which appear in the blastoderms thus formed are very 
that Seed of life when the embii is reduced (reduit) toa amissa. 
embryo, which it submits to constant pressure. From this there 
results a certain number = deviations and atrophies in the regions of the 
body submitted to pressur 
D e e which has nci hitherto considered inexplicable, results from 
an arrest in development of the caudal hood of the amnios ne. ch forces 
the posterior members, at the moment of their appearance, to reverse 
pee backwards, to come in contact with each other by oan exter- 
edges, and to unite themselves in this universal positio sq mete a 
a has in the beginning hydropsy of the vesicles whic the 
State of the encephalic organs. ropsy is found equally in the 
amnios, and sometimes, indeed, in the whole thickn 
which then — a general oedema, - result of a peculiar s state 
AMER. NATURALIST, VOL. III. 


