OBSERVATIONS ON H#MATOZOA IN CHYLON. 391 
The unrolling of the parasites would seem to precede its 
liberation from the corpuscle. This is obviously a critical 
moment in its life-history, but it is not known what happens 
next. 
Occasionally the bent forms are seen free in the plasma, 
but this we attribute to accidental rupture or liquefaction of 
the corpuscle. When the parasite normally becomes free it 
is probable that the corpuscle undergoes disintegration. 
We have named this species Hemogregarina nico- 
riz.! In the present stage of knowledge of the hamo- 
eregarines the specific differences are largely a matter of 
host, or, in other words, of environment. All authorities 
seem to be agreed that there are different species, and that 
it would be wrong to call all hemogregarines H. stepa- 
novi, following the example of Halteridium, all the forms 
of which are called H. danilewskyi. It will be seen below 
that there are, so far as we can tell, extraordinary differences 
in the life-histories of hemogregarines infesting different 
hosts. 
The fact seems to be that the parasites are hard to dis- 
tinguish in the immature, asexual, or hemogregarine phase. 
Finally, with regard to H. nicoriz, it may be mentioned 
that although the bent parasite is not more than about one 
half the length and one third the width of the corpuscle, yet 
the nucleus of the latter is displaced towards one end of the 
cell. 
In one or two cases the nucleus of the parasite has pre- 
sented the appearance of having divided into four daughter 
nuclei, two of which occur at one end and two at the opposite 
end of the body. We have observed no further indications 
of sporulation. 
IV. Tue HemMocrecGaRINE oF TROPIDONOTUS PISCATOR. 
The freshwater snakes of the Colombo district seem to be 
frequently the unconscious hosts of a blood-parasite which in 
Castellani and Willey, op. cit., p. 85. 
