No. 3.] UTERUS AND EMBRYO. 427 
The following additional points deserve notice: The serotina 
is about 1.5 mm. thick, and contains an enormous number of 
decidual cells, Cut 36. The cavernous, D’, and compact layers, 
D", are very clearly separated; the mucosa is sharply marked 
off from the muscularis, mc, although scattered decidual cells 
have penetrated between the muscular fibres. The muscularis 
is about 10 mm. thick, and is characterized by the presence 
of quite large and numerous venous thrombi, especially in the 
part towards the decidua. The decidua contains few blood- 
vessels. Upon the surface of the decidua can be distinguished 
a special layer of mingled hyaline and decidual tissue, which in 
many places is interrupted by the ends of the chorionic villi, as 
is well shown in Cut 36. The supposed gland cavities of the 
spongy layer, D’, are long and slit-like; they are filled for the 
most part with fine granular matter, which colors light blue 
with haematoxyline ; they also contain a little blood, sometimes 
a few decidual cells. 
I have seen in them 
also a few oval bod- 
ies several times 
larger than any of 
the decidual cells, 
and presenting a 
vacuolated appear- 
anee’; what these 
bodies are, I have 
not ascertained. In 
places the glandu- 
lar epithelium is 
distinct ; its: cells 
enSy greatly in aes Cut 37. — Decidual cells from the section represented 
pearance, neighbor- in part in Cut 36. a, 4, d, f, various forms of cells from 
ing cells being serotina; c, giant cell from the margin of the placenta; 
eé, clear cells from chorion; at a, seven blood globules 
have been drawn in to scale. X 545 diams. 
often quite dissimi- 
lar; nearly all are 
cuboidal, but some are flattened out; of the former there are 
some with darkly stained nuclei, but the majority of the cells are 
enlarged, with greatly enlarged hyaline, very refringent nuclei. 
The decidual cells are smaller and more crowded in the cav- 
ernous layer, and mostly larger in the compact layer — compare 
