1889.] Embryology. 171 
and that this feature testified more forcibly than anything else 
to their low affinities. They also described a community of 
structure between the modified syndemoses in certain Anura 
and the apparatus of the knee-joint in Mammals, and urged 
that the facts were such as to necessitate a reconsideration of 
the morphological value of the latter. 
EMBRYOLOGY.^ 
New Studies of the Human Embryo.— M. C. Phisalix' 
gives a very complete account of a human embryo of one cen- 
timetre (two-fifths of an inch) long. The method of plastic 
reconstruction from a continuous series of sections is carried 
out for the entire embryo. The organs which receive special 
attention and reconstruction are the cranial nerves and nervous 
system, the disposition of the valves and septa of the cavities of 
the heart, the origin of the pancreas, and Wolffian bodies. 
Many points dealt with by His have been more fully elaborated 
or corrected by Phisalix. The reconstructions seem to have 
been carried out with great care and accuracy, that represent- 
ing the relations of the cranial and spinal nerves from the side 
is very interesting ; the same may be said of the reconstruc- 
tions representing the alimentary canal and its appendages. 
The origin of the pancreas from two distinct diverticula will 
be noted by specialists as a matter of interest The great length 
relatively of the bronchi at this stage and the acute flexure of the 
branchial region are very strikingly shown, while the crowding 
together of the branchial clefts and the diverticula from them 
which give rise to the thymus gland are admirably shown in 
their relation to adjacent parts. But as the memoir is hard to 
understand without the figures which accompany it, the reader 
is referred to the original for fuller anatomical details. 
A curious fact is mentioned by the author in regard to the 
embryo described by him, viz., its want of perfect symmetry, 
though believed to be perfectly normal. The left side, espe- 
cially the region of the cerebral vesicles, was found to be larger 
iThis Department is edited by John A. Ryder, University of Pennsylvania, 
Philadelphia. ^ ^ 
. ''Etude d'un Embrvo humain de lo millimetres. Arch. de. Zool. Expr. 2 me 
Ser vi. 1888. Nos. 2 et 3. pp. 280-350, planches xiii-xviii and figs. A.-F. m 
