W. S. Patton 
97 
one. Salvin-Moore and Breinl, on the contrary, consider the blepharo- 
plast is an extra-nuclear centrosome; Woodcock however considers that 
this view is not supported by the evidence furnished by the trypano- 
plasmes. 
In the present state of our knowledge we think it would be of very 
little use to discuss the pros and cons of these disputes; we consider 
however that it is by no means proved that the trypanoplasmes afford 
any evidence on the structure of the trypanosomes. All the evidence so 
far collected (see p. 124) clearly suggests that true trypanosomes have 
originated from crithidia-like ancestors, and we believe that the study 
of these simple insect pai’asites will be a valuable guide to the study of 
the structure and origin of the trypanosomes. Quite recently the 
writer found a new flagellate in the Malpighian tubes of Musca 
domestica; this parasite is even more primitive in its morphology than 
any flagellate yet described, as its flagellum is entirely wanting and 
appears to be replaced by a simple elongation of its ectoplasm. It is 
hoped that the study of this parasite will throw some light on the 
nature of the flagellum and its connection with the blepharoplast; at 
present we think it is premature to theorize on the nature of these 
chromatic structures. 
In the section devoted to biological considerations Woodcock remarks 
on the various movements exhibited by trypanosomes and notes there is 
a great difference of opinion as to whether the flagellum or the 
undulating membrane play the principal part in the movements of 
trypanosomes. It has always appeared to us that the flagellum is the 
chief factor in the movement of these parasites, and this is very evident 
when living Herpetomonads are studied. We have seen many which 
travel quite as fast as T. lewisi. 
With regard to the peculiar phenomenon known as agglomeration, 
Woodcock states that, in the case of vertebrate trypanosomes, the para¬ 
sites collect together by their aflagellar ends, forming a multiple union 
or rosette. In Trypanosoma noctuae according to Schaudinn the 
parasites agglomerate by their flagellar ends. A great deal of confusion 
is here introduced by the use of the term “rosette”; by this term we 
understand a group of parasites which have resulted from the multiple 
segmentation of a single cell. In cultures of T. lewisi (figured by 
Laveran and Mesnil, 1904) and in Herpetornonas cidices (figured by 
Patton, 1907) the flagella are directed centrally; it should be noted these 
parasites are not adult flagellates. In the multiplication rosette of 
T. lewisi from the blood of a recently infected rat the flagella are directed 
Parasitology ji 
7 
