THH STRUCTURE OF TRYPANOSOMA LEWISI. 799 
thing, a body having the form of a disc which, seen edgeways, 
would appear rod-shaped, and in surface view would present 
a circular contour. This explanation is compatible with the 
facts stated above, namely that the rod-shaped type is darker 
in colour, that there are transitions between the two forms, 
and that the blepharoplast overlaps the round form, but is 
found close beside the rod-shaped form. I have not been able 
to convince myself that this explanation is either true or false. 
Salvin-Moore, Breinl, and Hindle (1908) are of opinion 
that the kinetonucleus is to be regarded as of the nature of a 
centrosome or blepharoplast, and use the term “ end-bead of 
the flagellum” for the granule termed by me the blepharoplast. 
The question is one that must be decided by developmental 
data; a true centrosome is pre-eminently a body of dynamic 
rather than static function. I do not desire, therefore, to 
argue the question in this memoir, in which I purposely avoid 
dealing with division-stages. I will only say that in refusing 
to allow the kinetonucleus the status of a true nucleus, the 
authors are ignoring a great deal of work by Schaudinn and 
others in support of this view. As regards the “ end-bead,” 
I am still of opinion that it represents a true centrosome 
or blepharoplast. In Trypanosoma grayi I found that 
division of the blepharoplast was invariably the first step in 
the division of the trypanosomes. 
The trophonucleus is at first very puzzling, on account of 
the extraordinary difference in its appearance after the 
Romanowsky stain, now so much in use, and all other stains. 
The coarse ‘‘ Romanowsky splotch” seems at first sight to 
have nothing in common with the delicate, refined structure 
seen after iron-hematoxylin or Twort’s stain (compare figs. 
60-63, with figs 10, 11, and 82-87). I have already attempted 
above an explanation of the vagaries of the Romanowsky 
stain; my reasons for regarding the results of this stain as 
departures from the truth are simply founded on the facts— 
first, that the condition seen after iron-hematoxylin is also 
seen in the standard preparations, in the living condition, and 
after every other nuclear stain known to be of value as such; 
