204 University of California Publications in Zoology [Vol. 16 



Piroplasma has been described by Nuttall and Graham-Smith 

 (1906, 1907) as possessing, in many individuals, a blepharoplast, so- 

 called. This is a transient structure with no relation to a motor ap- 

 paratus nor to the division process. Neumann (1909) figures, from 

 the bat-mite, a species of Achromaticus which becomes a flagellate 

 form in its development. As already pointed out by Minchin (1912), 

 a trj'panosome from the same host has probably been confused with 

 the Piroplasma in this case. A comparison of his figures and Giemsa- 

 stained preparations of the small forms of trypanosomes becomes very 

 instructive in the light of this suggestion. 



The figures of flagellated forms of Babesia canis observed by 

 Breinl and Hindle (1908) in the blood of dogs dying from piroplas- 

 mosis have attached to them the strongest doubts. They are very 

 possibly intestinal flagellates such as may be occasionally found in 

 the blood under pathological conditions, and may be in no way re- 

 lated to the life-cycle of Babesia canis. 



Finally, Hartmann's contention (1910) that the microgametes of 

 Proteosoma possess an undulating membrane rests on unverifiable evi- 

 dence and is not supported by the results of other investigators. The 

 occurrence of flagellated swarm-spores and gametes in other groups, 

 as the Amoebina, Volvocidae, Coccidia, etc., has never been used as an 

 argument for placing these widely diverse groups in one order, and 

 yet tliis is presented in good faith by Hartmaun as one of the reasons 

 for including the Proteosoma with the trypanosomes. 



The work of Gonder (1910) on Theileria and Babesia, of Neumann 

 (1908) on Plasmodium, of Yakimoff, etc. (1911), on Achromaticus, of 

 Nuttall and Graham-Smith (1906, 1907), and others, in spite of the 

 fact that they find "blepharoplasts" or even traces of flagella, all 

 afford the strongest proofs of the non-haemoflagellate affinities of these 

 forms, as well as the undoubted resemblances in their developmental 

 cycle to that of the Coccidia, in so far at least, as the course of devel- 

 opment has been figured by these investigators. 



In fact, we might go a step further and point out the similarities 

 existing between the life-cycles of the Haemosporidia and many of 

 the Rhizopoda, showing a well-marked differentiation into sexual and 

 non-sexual cycles, with a distinct alternation of generations. TricJio- 

 sphaerium sieboldi from tlie Rhizopoda and Plasmodium vivax from 

 the Haemosporidia may be taken as typical examples. The life-cycle 

 in each consists of the following phases; trophic phase, or growth- 

 period, followed by schizogony, which may be repeated a number of 



