110 C. CLIFFORD DOBELL. 
account of the Flagellata which has appeared (47), Senn 
(1900) regards conjugation as still unproven in the group. 
Apart from the Phytomonadina all accurate knowledge of 
the matter has been acquired during the last half-dozen years. 
The most important researches are those of Prowazek and 
Schaudinn, the latter throwing much light upon the trypano- 
somes and their allies. In the Phytomonadina conjugation 
has been demonstrated in many genera: e. g.in Polytoma 
(by Krassilstschik [29], Dangeard [16], Prowazek [86], and 
others) ; in Chlamydomonas, etc., by Dangeard (14, 15) ; 
in Dunaliella (Teodoresco [50]), Volvox, Pandorina, 
and others. 
Goldschmidt (22) has just worked out a complete life-history 
in the Rhizomastigina—in Mastigella. It would appear 
from his account that the mastigamoebe are closely allied 
to the Rhizopoda, for he describes karyokinesis, formation 
of gamete-nuclei from chromidia, differentiated micro- and 
macro-gametes, etc., which strongly recall the conditions seen 
in rhizopods.! 
Apart from these two groups—the Phytomonadina and 
Rhizomastigina—conjugation has been shown to occur in 
Monas vivipara (36) and Bodo lacertz (89) among the 
Protomonadina, and in the following members of the 
Polymastigina: Trichomonas intestinalis (44,89), Hexa- 
mitus intestinalis (89), Lamblia intestinalis (44). 
It has also been proved to take place in Trypanosoma 
lewisi, Hemoproteus (Halteridium, Trypanosoma) 
noctuz (48), and in Herpetomonas musce-domesticxe 
(38). In all these forms heterogamy is found. But auto- 
gamy takes place in some flagellates, e.g. in Trichomastix 
lacerte (89), Herpetomonas musce-domestice (38), 
Bodo lacertez (89), ete. Sexual differences between the 
1 Perhaps Pseudospora should be considered in the same category. It 
certainly shows affinities with the Rhizopoda, but from Miss Robertson’s 
recent paper, ‘Quart. Journ. Micros. Sci.,’ vol. 49, 1906, p. 218, it is not 
clear to me how far gamete-formation in this animal corresponds with that of 
the Mastigamcebee, 
