NOTES ON SPOROZOA — IV. 
215 
IV. The Nuclear Structure op Leucocytozoon and 
Halteridium; the Significance op the So-called 
Binucleate Condition in these Forms, and its bearing 
UPON the Affinities op the HiEMOSPORiDiA. 
The observation of tlie occurrence of a distinct karyosoine 
in certain Hiemogregarines led me to study agaiu, from tliis 
point of view, the much-discussed nuclear condition found in 
the gametocytes of Leucocytozoon and Halteridium. 
As is now well known, female individuals of both these 
parasites, when stained by some modification of the Roman- 
owsky method, show besides the ordinary nucleus, which is 
stained red, another very definite nuclear body, which stains 
much more deeply than the other, and at times appears almost 
black ; this additional chromatic element may be either close 
to (in contact with) or quite separate from the nucleus. In 
the case of Halteridium this body has, in female individuals, 
the form of a conspicuous grain, but in the distinctive indi- 
viduals which have been regarded as neutral or “ indifferent ” 
(which, it may be incidentally remarked, seems to occur only 
rarely), it is even more prominent and may be almost as large 
as the nucleus. In the case of male individuals, however, I 
have not succeeded in making out anything comparable to this 
structure. As I have previously described and figured the 
appearance shown by Hal ter i di u m f r i n gil 1 le, when stained 
by Gienisa, I need not refer further to it ; I have found exactly 
the .same appearance in Halteridium noctuae of the little 
owl. 
In the case of Leucocytozoon ziemanni, the celebrated 
Leucocytozoon of the little owl, the additional chromatic 
body is very large and prominent in the female gametocytes 
(PI. 10, figs. 4-6), and by no stretch of imagination can it be 
regarded merely as a grain ! Anything more like the tropho- 
nucleus and the kinetonucleus of one of the large “blue” 
Trypanosomes present in the same bird might be expected to 
appear, in a resting, intra-cellular condition, it is impossible 
