NOTES ON SPOE.OZOA — 1[. 
177 
one side, which probably represents tlie characteristic element 
above described (cf. fig. 8). 
The effects of the parasite on the host-cell are very pro- 
nounced and characteristic, as is well known to be the case, 
of course, in Karyolysus. The gradual alteration of the 
red blood-corpuscle and its appearance when infected by the 
different forms of parasite merit description, however, since 
this change is of great importance and assistance both in 
determining the relation to each other of the two chief types 
I have described, and also in connection with the question 
of the various species of Ilmmogrognrine (Karyolysus) 
said to occur in this lizard. The earliest change in the 
appearance of the liost-cell which I liave noticed is drawn 
in fig. 2 (from a Giernsa smear). The parasite infecting 
this corpuscle is one of the smallest observed, and has 
the nucleus centrally placed. Comparing the liost-cell 
in tliis case with an ordinary uninfected red blood- cor- 
puscle, its nucleus is found to be already distiiictly larger, 
i. e. li 3 ’pertrophied, but still oval in shape and not much 
elongated. The cytoplasm of the corpuscle is also slightly 
liypertrophied, but it is still stained to about the same degree 
and shade of colour as in an uninfected cell. This is, 
however, almost the only instance I have noticed where the 
cytoplasm appears stained similarly to what is the case in an 
uninfected cell. It is remarkable how quickly the presence 
of a Kary olysus-individual in a corpuscle produces some 
effect on the cytoplasm which results in a complete alteration 
of its staining properties. In nearly all the corpuscles 
infected with this Ilocmogregarine, the cytoplasm has either 
taken up the stain only slightly, being faintly coloured, or 
else is very pale, practically unstained, so that it is often a 
matter of extreme difficulty to discern it at all. This is 
especially the case in wet preparations, stained by iron- 
htomatoxylin ; and in this respect Karyolysus differs 
markedly from certain other intra-cell ular parasites of red 
blood-cells, of which I have preparations stained in a similar 
manner. For example, in Hm mogregar i n a triglae (cf. 
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