10 PROF. E. A. MINCHIN ON PROTOZOAN [Jan. 12, 
does not exhibit them in their true proportions. The flagella also 
share in the general enlargement after the Romanowsky stain, and 
appear very much thicker than they do after iron-hematoxylin, 
which shows them as very delicate filaments; they give up the 
stain more readily than do the true chromatic structures. 
The trophonucleus is very different in its structure from the 
kinetonucleus. After iron-hematoxylin (Plates IV. and VY.) it 
appears as a clear space, oval or round, limited by a faint but 
quite definite membrane, which, when carefully examined, appears 
egvanular and uneven in thickness, and is probably composed of 
gvanules of chromatin connected together; it is therefore not a 
true nuclear membrane, in the sense in which the term is used 
for Metazoan nuclei. The trophonuclear membrane is much less 
distinct in Zrypanoplasma than in Trypanosoma; a difference 
perhaps largely due to its being obscured in the former genus by 
the numerous and deeply staining cytoplasmic granulations. In 
the space enclosed by the nuclear membrane lie one or more 
karyosomes, rounded bodies often very large, and staining very 
deeply with iron-hematoxylin. The karyosomes appear to me to | 
be simply masses of chromatin; they retain the stain very tena- 
ciously. Typically there is a single karyosome placed more or less 
centrally, but their size, number, and arrangement vary greatly, 
as will be seen by reference to the figures and special descriptions 
of the species. In the space between the karyosome or karyosomes 
and the nuclear membrane there are found minute chromatin 
granules, often disposed so as to leave a clear space round the 
karyosome ; the granules themselves are often so minute as to be 
scarcely visible. 
Where, it may be asked, are the definite chromosomes, eight in 
number, surrounding the karyosome, so often described by 
Schaudinn, Léger, Keysselitz and others ¢ Where indeed! I can 
but describe what I have seen, and I have never seen, after iron- 
hematoxylin, more than I have described above. Possibly the 
Schaudinnian chromosomes make their appearance at certain 
stages of the development or phases of the life-history. I can 
only say that they have never revealed themselves to me in any 
of my preparations. After the Romanowsky stain, it is true, a 
ereat variety of appearances can be seen, impossible to interpret 
in a uniform manner : sometimes the whole tr ophonucleus appears 
an even red mass, sometimes it shows coarse granulations disposed 
in various ways; in all cases its great difference in size, structure, 
and appearance from what is seen in the iron-hematoxylin pre- 
parations is quite bewildering. I have put forward above, in the 
section dealing with technique, what I believe to be the expla- 
nation of this. I hope to discuss the whole question much more 
fully in dealing with Trypanosoma lewisi elsewhere. 
Liihe has given * two figures of the trypanoplasm of the carp 
stained with iron-hematoxylin. He figures the trophonucleus as 
* In Mense’s ‘ Handbuch der Tropenkrankheiten,’ iii. p. 83, fig. 5. 
