early 'placenta of Macacus nemestrinus. 311 
a. capillary vessel (Fig. 6 11 i”). 
b. red blood-cells. 
c. nucleus of an endothelial cell. 
cl. red blood-cell outside the capillary vessel. 
e. the last endothelial cell of the capillary wall. 
f. a large cell with rosette-like nuclear figure. 
y. remnant of partition between capillary vessel and inter- 
villous space. 
h. intervillous space. 
i. gap in capillary wall, allowing escape of blood-cells. 
Fig. 8. From Section 274 (magnification &c. as in Fig. 7). This gives 
another illustration of the fate of the capillary endothelium where 
invaded by embryonic tissues. The capillary wall simply breaks 
down and the blood then bathes the embryonic cells. Red blood- 
cells have also escaped into the maternal tissues. In the blood 
stream are seen two examples of leucocytes with nuclei arranged 
in “ tetrads ” (cf. text). 
a. capillary vessel. 
b. red blood-cells. 
c. nuclei of endothelial cells. 
c. nuclei beyond which no endothelium is recognisable on 
embryonic side. 
d. red blood-cells in intercellular spaces. 
e. a leucocyte with curious nucleus (“ tetrad ”). 
e . a leucocyte in an intervillous space. 
f indefinite material, probably remains of syncytial tissue. 
g. commencement of an intervillous space. 
Figs. 9, 10, 11. Sections 263, 265, 267 (magnification etc. as in Fig. 7). 
The appearances here seen bear the interpretation that a mass of 
embryonic cells of syncytial type approaches (Figs, 9, 10) and invades 
(Fig. 11) the cavity of an uterine gland into which haemorrhage 
has previously taken place. 
Fig. 9. a. lumen of uterine gland. 
b. degenerating gland-epithelium. 
c. mass of tissue regarded as embryonic (syncytial). 
d. cells between embryonic tissue and lumen of gland. 
e. red blood-cell. 
