« INFECTIVES GRANULES » OF PROTOZOA 543 



racier of the boily s^en in Protozoa (and in unicellular plants) 

 arose by formation of a definite cell-nucleus from the whole or 

 a part of Ihe scittered chromidial grains. Consequently the 

 cliromidial buds, or any olher stages of Protozoa in which 

 the chromatin is found only in the form of scattered chromidial 

 grains, might verv well be regarded as of phylogenetic and 

 recapitulative significance. I doubt, however, wh(4ber Ihe 

 minute buds ot trypanosomes and bsemogregarines can be 

 interpreted as recapitulating a still older phylogenetic stage, 

 similar to that perhaps représente I by the Chlamydo/o;i at 

 the [iresent day, a stnge in which the body consists of a single 

 chromatin-grain. It seems lo me much more likely that the 

 minute buds of trypanosomes and h*mogregarines have niiscn 

 by a si^condary reduction in size and structure of chromidial 

 buds such as those formed in amoeba^, and other Protozoa, 

 probably as an adaptation to para'^ilism in blood; and that 

 conse<iuently their minute size and simple structure mu^t not 

 be regarded as characters which are capable of a phylogenetic 

 interpretation. 



1 would like lo point out, finally, that the discoveries of Fry 

 and Ranken and of Henry conslilule, in my opinion, a very 

 important advance in our knowledge. They show that repro- 

 duction by formation of endogenous chromidial buds occurs 

 in the Hsemotlagellates and Haimosporidia, groups in which it 

 had not been suspected hitherto to take place (1). It may 

 well be, therefore, that this method of reproduction is of much 

 wider occurrence among Protozoa than has been supposed up 

 to thft present, and that in many forms, such as Lamhiia, for 

 example, where division is not often found, it may be on 

 method of the reproduction of Ihe organism. Light is also 

 thrown by it on the nature of ihe « chromatoid grains » of 

 trypanosomes, which have heen asserted to be, in most cases, 

 grains of the nature of volutin; but the proof that they can 

 give i'i«e to « secondary » nuclei puts it beyond all doubt that 



(t) I do not refer here specially to the observations of Balfour on spiro- 

 clijetes. because I am unable to regard these organisms as true Protozoa, 

 and I think it possible that the « infective granules » or « coccoi'd bodies » of 

 spirochfetes may require a different cytological (and phylogenetic) interpre- 

 tation from those of trypanosomes, in spite of their similarity in appearance 

 and function. 



