cc INFECT IV ES GRANULES » OF PROTOZOA 
543 
racter oi the body scen in Protozoa (and in unicellular plants) 
aros<3 by formation of a delinite cell-nucleus from the whoie or 
a part oi Ihe scattered chromidial grains. Gonsequently the 
chromidial buds, or any other stages of Protozoa in which 
the chroma lin is found only in tlie for m of scattered chromidial 
grains, might very well be regarded as of phylogenetic and 
recapitulative signilicance. I doubt, however, whether the 
minute buds ot trypanosomes and hæmogregarines can be 
interpreted as recapitulating a still older phylogenetic stage, 
similar to that perhaps représente 1 by the Chlamydozoa at 
the présent day, a stage in which the hody consists of a single 
chromatin-grain. It seems lo me much more likely that the 
minute buds of trypanosomes and hæmogregarines hâve arisen 
by a secondary réduction in size and structure of chromidial 
buds such as lliose formed in amœbæ and other Proto/oa, 
probablv as an adaptation to para^itism in bloo I ; and that 
consequenlly their minute size and simple structure must not 
be r egarded as characters which are capable of a phylogenetic 
interprétation. 
1 would iike lo point out, finally, that the discoveries of Fry 
and Ranken and of Henry conslifule, in my opinion, a very 
important advance in our knowledge. Th ey show that repro- 
duction by formation of endogenous chromidial buds oceurs 
in the llæmoOagellates and Hæmosporidia, groups in which it 
had not heen suspected hitherto to take place (1). It may 
weli be, therefore, that this melhod of reproduction is of much 
wider occurrence among Prolozoa than lias been supposed up 
to the présent, and that in many formas such as Lamblia, for 
example, where division is not often found, it may be on 
method of the reproduction of Ihe organism. Light is olso 
thrown by it on the nature of ihe « chromatoid grains » of 
trypanosome^, which hâve been asserted to be, in most cases, 
grains of the nature of voiutin; but the proof that they can 
give rise to « secondary » nuclei pu ts it beyond ail doubt that 
(1) I do not refer here specially to the observations of Balfour on spiro- 
chætes, because I am unable to regard these organisms as true Protozoa, 
and I tbink it possible that the « infective granules » or « coccoïd bodies »> of 
spirochætes may require a different cvtological (and phylogenetic) interpré- 
tation from tliose of trypanosomes, in spite of their similarity in appearance 
and function. 
