223 
watched. Up to a certain point observations on trypanosomes in 
cultures may be very valuable here. 
Bouet (Culture du Trypanosoma de la grenouille, Annales de l’lnst. Pasteur, 
Yol. XX, No. 7, page 364) has obtained a very large part of the “ swarm ” cycle (34) of 
this parasite in cultures. 
Novy and MacNeal, in their studies on mammalian and bird trypanosomes, 
illustrate forms which are interesting in this connection. Life History of Trypano¬ 
soma Icaiisi and Trypanosoma brucei, Journal of Infect. Diseases, Vol. I, No. 4, 
Xov. 5, 1904, p. 517. On the trypanosomes of birds, Journ. Infect. Diseases, Vol. 
II, No. 2, March 1, 1905, p. 256. 
Cerquira, in a thesis published at Rio de Janeiro, describes a most interesting 
development in bird trypanosomes in cultures. It bears evident analogies to the 
multiplication process described in T. loricatum (34) (reviewed in Journal of Tropical 
Medicine, April 1, 1907, p. 118). 
A process which has been seen by many observers in trypanosomes 
ingested by arthropoda is the formation of spherical bodies without 
undulating membrane, flagellum or, at first, differentiated blepharo- 
plast. Similar forms have been reported by many different authors 
in most of the mammalian trypanosomes when they are placed in 
various “ unfavourable circumstances,” 19 such as in moribund animals, 
in the cerebro-spinal fluid, in organs, kept preparations ol fresh blood, 
cultures, gut of lice, fleas and biting flies. 
These rounded parasites bear a most striking resemblance to the 
rounded form of Trypanosoma loricatum which commences the 
interesting cycle of “ swarm ” development first described by 
Danielewsky. 27 These forms of the mammalian parasites are formed 
in much the same way as are the rounded frog trypanosomes. Does 
their further development proceed in the same way ? (see footnote to 
page 62 of 27 ). The work of the following observers shows that there 
may be some resemblance between their subsequent stages. 
Bradford and Plimmer (24) describe the rapid division of spherical “amoeboid 
forms” of T. brucei in the blood of a vertebrate host. 
Prowazek (22) also reports the division of such bodies in T. brucei ; and 
describes the formation of similar spherical bodies in T. lewisi ingested by a louse ; 
and he suggests that these later develop a flagellum. 
Koch (9) describes the formation of rounded forms, which subsequently develop 
a flagellum, in cattle trypanosomes ingested by Glossma. In their deve opmen 
these parasites pass through a herpetomonas-like stage. 
Lingard (28) describes certain developmental processes in trypanosomes o 
ndian cattle where similar rounded forms occur. 
Moore and Breinl (26) have observed similar forms in T. gambiense, t special y in 
anim als treated by atoxyl; their further development has not been followed. A seco 
‘vpe of rounded form, produced by the extrusion of the nucleus from an ord 
trypanosome, was observed to produce a minute flagellum. 
