NOTES ON STRUCTURE, ETC., OF ELEPHANT’S PLACENTA. 15 
ference of this pigment. The appearances seem to favour 
the idea, namely, that leucocytes convey the pigment, which 
is formed or deposited by the syncytial layer, into the maternal 
layer, where they disintegrate, and so discharge their load of 
pigment. 
It seems possible that these leucocytes are derived from 
the endothelial layer, as suggested by the forms shown in 
fig. 14, and by the probable method of development as 
indicated under Section II. of this paper. 
Another possibility suggests itself. The large number of 
leucocytes in the foetal fibrous tissue alluded to above is very 
remarkable. These are spherical cells with small, deeply- 
staining nuclei, and are mostly without pigment granules. 
The size and character of the nucleus correspond with the 
size and character of the nucleus in the pigment-loaded cells 
of the maternal channels. Do these leucocytes migrate from 
the foetal fibrous tissue through the syncytial layer, and there 
pick up the pigment and pass on to the maternal stream ? 
It is possible to find in the syncytial layer small nuclei 
which correspond in size and staining affinity with these 
leucocytes, which nuclei are certainly not the true nuclei 
belonging to the syncytium. 
It is rather significant that in the immediate neighbour- 
hood of one of these foetal leucocyte-containing spaces the 
adjoining maternal channels are more crowded with pigment- 
laden leucocytes (v, fig. 6) than elsewhere. 
The Subcircular Bodies. 
The position of these peculiar structures was described by 
Owen and Chapman, and a more minute examination was 
made by Turner, who correctly describes them “as composed 
for the most part of fine fibres.” 
In transverse section figure (9) they are seen to be com- 
posed almost entirely of fine fibres, and probably some 
gelatinous matrix. The fibres are especially abundant, and 
