FURTHER NOTES ON A TRYPANOSOJEE. 
133 
me to be chromatin, but in Twort’s stain they do not take up 
the red colour. I do not lay very much stress on this point, 
as it is just in a question of this kind that I think such a stain 
as Twort^s is rather unreliable. There seems to be in the 
membrane, as in other parts of the nucleus, an underlying 
substance of an achromatic nature, in or on which the chi’o- 
matin is deposited. 
This nucleus is exceedingly constant in all the stages of 
the parasite as found in the leech, the only variation lying in 
slight differences in the condensation of the chromatin in the 
karyosome and the membrane. 
The pictures presented in the dried Giemsa preparations 
differ greatly from this account. The most curious feature 
about this is that some of the Giemsa appearances give a very 
tolerably accurate representation, while others depart com- 
pletely from the type shown by the wet method. The eight 
chromosomes so often seen in the Giemsa nuclei are not to be 
detected in the hmmatoxylin films. The rays and the con- 
densations on the membrane are, I have no doubt, the 
manner in which these appear in the wet films. The number 
of the rays can, liowever, not be made out, as they are 
excessively fine, nor do the condensations on the membrane 
stand out sufficiently separately to be considered as individual 
structures. The Giemsa stain, of course, always increases 
the apparent size of any nuclear element into which it 
penetrates. 
The kinetonucleus takes all the stains mentioned with srreat 
intensity; it is relatively large and rod-shaped. In close 
proximity, and apparently attached to it, lies the blepharo- 
plast (Minchin, ‘ Quart. Journ. Micr. 8ci.,’ May, 1908, vol. 52), 
(figs. 9-10, etc.). 
This structure will be more fully considered when the 
development of the flagellum is discussed. The blepharo- 
plast stains with iron luematoxylin, but the stain is washed 
out more readily than from the nuclear structm*es ; it 
appears grey-blue and rather faint with Delafield, and is 
difficult to detect at all in Twort preparations. Tlie flagellum 
