NOTES ON STRUCTURE, ETC., OF ELEPHANTS PLACENTA. 37 
Fre. 18.—A rather more internally placed area. Here the trophoblast has 
degenerated into a syncytium, and the adjoining syncytia fuse. In the left- 
hand corner an advanced stage is illustrated. Within the syncytium certain 
spaces are recognisable (m. ch.) in which numerous cells are floating (4. ¢.). 
x 325. 
Fie. 19.—Some of these large rounded cells mentioned under fig. 23, seen 
on the maternal surface outside a sharply defined membranous layer. X 400. 
Fic. 20.—Similar cells just within the membranous layer. x 400. 
Fic. 21.—A piece taken from about the spot where the line 16 ends in 
fic. 15. Here the new blocd-channel is clearly seen to be between the 
trophoblast cells, not within them. x 400. 
Fic. 22.—A large maternal channel derived from inter-cellular (inter- 
villous) space. The walls are well marked, and on their outer side are 
supported by the columnar cells of the trophoblast. Compare fig. 24. Inside 
are many blood-cells, and along the border large cells which give rise to 
smaller ones. Are they maternal in origin? x 490. 
PLATE 5. 
Fic. 23,—A piece of the limiting homogeneous layer, showing one apex of 
a villus abutting against it. ‘The nuclei passing off into it are seen getting 
less and less distiuct as they pass further away. Beneath this layer is an 
outer layer destitute of the above-mentioned oval nuclei, but some tissues 
containing loose rounded cells witli small nuclei probably of maternal origin. 
x 400. 
Fic. 24.—Part of a large intervillous space forming one of the chief 
blood-channels for maternal blood. At /. c. the foetal villus with its capillaries; 
at ¢r. the trophoblast layer shrunk away from its mesoblast and forming the 
wall to the large blood-channel J. C. H. in which many large cells (exd) and 
masses of fragments can be observed. x 400. 
Fie. 25.—A portion of a transverse section of one of the few blood-vessels 
found attached to the rough median area of Owen’s specimen. The endothelium 
has the appearance of being in a state of proliferation. It is assumed to be a 
maternal artery. x 400, 
