NOTES ON SPOEOZOA II. 
175 
liost-cell is still apparent tlie delicate capsule does not stand 
out in sucli a marked manner, but its presence is clearly 
indicated, in my opinion, by the following consideration. 
Many, of the older forms, those, i.e., of the second type, in 
which the nucleus is situated near one end, appear very dark 
in “ wet preparations, being stained diffusely and more or 
less uniformly, so that it is very difficult to distinguish the 
nucleus. This appearance is really owing to the stain 
deposited inside the capsule or envelope not having been 
sufficiently extracted subsequently, the differentiating agent 
not having had time to penetrate properly inside the capsule, 
thus leaving the parasite overloaded with stain. I have never 
found this state of things, it should be noted, in the younger 
parasites, with the nucleus still near the middle ; hence the 
capsule does not appear to be formed during the early phase. 
This capsule or envelope present in certain forms of 
Karolysus appears to be very similar to that described in 
the case of small forms (young schizonts) of Haemo- 
gregarina triglm by Minchin and Woodcock (20). In the 
case of Karyolysus, however, I am inclined to think that the 
capsule is rather a definite envelope formed by the parasite 
than merely a sheath or altered layer of the cytoplasm of the 
blood-corpuscle (cytocyst), as we regarded it at the time in II. 
trigla); its persistence and distinctness in such individuals 
as those drawn in figs. 37 and 38 supports this view.^ 
Considering now the nuclear structure in detail (as it is 
seen in “wet” preparations, stained with iron-hmmatoxyliu), 
in the first type of individual, where the nucleus is situated 
near the centre of the parasite, the most striking feature is 
the very frequent occurrence of a conspicuous, deeply staining 
body, which is closely associated with the nucleus, lying at 
one side of it, contiguous to, but not actually forming part of, 
the general nuclear substance (figs. 19, 21-25). This latter 
consists, as in other llmmogregariues, of a network containing 
small but fairly prominent grains of chromatin, !iiost of which 
' The mode of origin of the capsule may he really the same, of course, 
in H. trigla) also. 
