284 
LILIAN SHELDON. 
eggs, the yolk is rendered much less brittle than after auy other 
methods which I have tried; the protoplasm and nuclei are 
well preserved, and also the egg-shell expands and lies at some 
distance from the periphery of the ovum, and so can easily be 
removed. The eggs were all stained with picro-carmine, and 
passed through the various strengths of alcohol in which a 
small quantity of picric acid was dissolved. 
The embryos, with the exception of a few quite old ones, 
were all of stages between those shown in figs. 10 and 15 in 
my last paper (4), that is, they came in age between those 
received in December and April respectively. 
My material is again very incomplete, and the new stages 
which I shall describe, though they throw some light on the 
early development, are very few, and do not unfortunately by 
any means fill up the gaps which were left in the account of 
the development given in my last paper (4); but it seemed 
advisable to publish my results, in the hope that they might 
prove useful if anyone should have the opportunity of working 
on the development of this interesting species with a better 
supply of material than I have been able to obtain. 
The ovum, which represented the latest segmentation stage, 
described and figured (fig. 10) in my last paper (4), was one 
which was taken out of the uterus in December. In it the 
nuclei were present round slightly more than half the ovum, 
lying in small masses of branched protoplasm. The central 
one of these nuclei lay on the surface and showed signs of 
karyokiuetic figures. There were also two or three proto- 
plasmic masses in the central yolk. I have now (in the 
January lot) several stages later than this, which show that the 
nuclei in the centre of the surface of the ovum beneath which 
they lie multiply with considerable speed and very much more 
quickly than those over the rest of the ovum, a condition 
which is shown in fig. 4, until by their repeated increase the 
egg acquires the form shown in fig. 11 (4), which represented a 
transverse section through an April ovum. In the ovum there 
figured there is a specially-marked area of reticulate proto- 
plasm, containing a large number of nuclei extending through 
