52 THE OVUM AND 
part of which flows slowly out. Around this mass lies a more 
consistent, cohering, membrane-like stratum, which lines the 
cavity of the little egg. When a portion of this mass is exa- 
mined under the microscope, a great many round and very trans- 
parent vesicles or cells are observed in it, each of which encloses 
a dark corpuscle resembling an oil-globule. Many such globules 
float about free, and in addition to them there is also a good 
deal of minutely granulous substance present. In order, how- 
ever, to examine this mass in a perfectly natural condition, the 
use of water must be avoided; one of the little eggs, of from 
half a line to a line in diameter, should be placed upon the dry 
object plate, and then pierced, a drop of its contents bemg 
allowed to flow out. This drop will be found to consist entirely 
of very pale cells, most variable in size, each one containing a 
round globule, the size of which is about proportionate to that 
of the cell. This globule or nucleus resembles an oil-globule, 
in consequence of its dark outline, (see pl. II, fig. 3.) Many 
of these cells with their nuclei are so small, that, when lying 
close together, they might be regarded as a merely granulous 
substance; the cells may, however, be recognised with a fa- 
vorable light. Some of the larger ones occasionally contain 
two or three of the globules or nuclei before mentioned. The 
contents of the cells are usually quite transparent, but some 
isolated ones are seen, in which a minutely granulous precipi- 
tate has formed. These cells are enclosed within the egg, in 
a small quantity of transparent fluid. In order to explain’ the 
somewhat variable appearance which the contents of the egg 
assume after contact with water, a small one should be placed 
upon a glass with a drop of that fluid, and some of its contents 
pressed out whilst under the microscope. A quantity of these 
cells will then be seen to burst quite suddenly in the water, 
precisely like soap-bubbles in the air. In consequence of their 
paleness, the fact of the bursting is rendered manifest, in the 
first instance, only by the sudden motion of the nucleus, which, 
together with some minutely granulous substance, remains 
behind. If these cells were solid, although ever so soft, this 
sudden bursting would not be possible. They are therefore 
true cells. I cannot say whether the globule enclosed in them 
is to be regarded as the nucleus. Although it resembles an 
oil-globule, it does not appear to be fat; for if acetic acid be 
