104 
A New Gregarine 
The most striking change that lias occurred in it is the loss of all 
its basic staining substance or chromatin, which cannot be seen in any 
form. The band-like riband of chromatin seen in the sporont has 
disappeared. The spherical bodies occurring in the nucleus of the 
sporont are now very numerous; the nucleus contains many of them 
irregularly scattered through the “ karyolymph,” and they may vary 
considerably in size (Fig. 20). 
The significance of these changes seems very oKscure. The out¬ 
standing feature is the loss of all chromatin as such: the only 
explanation is that it is dissolved and utilised in some way which is 
essential to the cell at this stage. The chromatin band of the vegetative 
cell is I think a kind of plastid or store-house of chromatin intended for 
use during the sexual processes which are now taking place. In this 
form the cyst is voided in the excreta. 
In the excreta the cyst appears to the naked eye as a minute pearly 
white object, but a little later (24 hours) it begins to be crinkled on the 
surface and on the second day is smaller and also presents a new and 
characteristic appearance. It consists of a well-defined spherical brown 
core surrounded by a crinkled fibrous-looking epicyst which is not 
itself spherical but rather expanded around the equator of the cyst as 
a sort of flange (Fig. 23, 3rd day). The size of such a cyst is about 
75 /ti in diameter. 
At first the nucleus can sometimes be seen as a clear area in each 
hemisphere, and the partition between these two may be very distinct. 
When examined in vivo under the microscope (Fig. 24), during the first 
24 hours there is considerable contraction of the cyst, and the ectoplasmic 
partition quite disappears. The epicyst increases as the endoplasmic 
core decreases in size. The latter appears to be merely granular up to 
about 54 hours after the cyst becomes free, and then suddenly appears 
filled with a mass of oval spores. Later on the mere wetting of a cyst 
filled with spores is accompanied by their discharge, their place being 
taken by a minute bubble of water (or air?). Two cysts, lying side by 
side, may differ in respect to the time they occupy in undergoing these 
changes, in one instance for example the third stage seen in Fig. 24 
had not been passed after 72 hours. 
A new structure also appears in the cyst at a variable time after, 
and sometimes even before, it is excreted. This is a striated band which 
surrounds the endoplasm but is internal to the hbrous-looking epicyst. 
It probably represents a system of minute tubes radially disposed round 
the endoplasm. It may be derived from the ectosarc of the sporont 
