THE INTESTINAL PROTOZOA OF FROGS AND TOADS. P| 
flagellar apparatus in trypanosomes—without, however, its 
strict homology with the organ in plant spermatozooids being 
insisted upon. Many different opinions have existed regard- 
ing the real nature of this body. Rabinowitsch and Kempner 
(75) regarded it as a “nucleolus,” though why it is difficult to 
see. Wasielewsky and Senn (85) believed it to be merely 
a cytoplasmic thickening—a structure independent of the 
nucleus. Laveran and Mesnil (65) considered that the 
blepharoplast should be regarded as a kind of centrosome— 
a view which they had already advocated in 1900 (‘CR. Soc. 
Biol.’). The view was based upon analogy with the struc- 
ture of sperms and some flagellates, for no evidence of the 
blepharoplast functioning as a division centre had been 
brought forward. But it was a suggestive working hypo- 
thesis. Bradford and Plimmer (52) called the blepharoplast 
a “micronucleus,” because they believed it played a part in 
the “conjugation” which they observed. ‘This comparison 
with the organella of Infusoria probably rested upon an 
incorrect interpretation of the phenomena observed. 
The whole matter was apparently cleared up by Schaudinn 
(79) in his study of the life-cycle of Hamoproteus 
(Trypanosoma) noctuz. From this famous investigation 
it appeared that the trypanosome blepharoplast should really 
be regarded as a nucleus specially differentiated to subserve the 
locomotory functions of the cell—a kinetonucleus, which played 
its part in conjugation, ete., just like any other nucleus. Far 
from being itself a centrosome, Schaudinn showed that it 
actually contained a division centre, just like that of the 
trophonucleus. 
Starting out from Schaudinn’s discoveries, Gross (59) made 
a very suggestive comparison between a sperm anda trypano- 
some, but in a converse manner to that which had been made 
by Laveran and Mesnil: that is to say, he suggested that the 
end-knob (centrosome) of the sperm might be regarded as a 
kinetonucleus, the sperm thus being binucleate like a trypano- 
some, 
More recently a very careful investigation of the morpho- 
