4 PrQt, 
XVIII. PROTOZOA. 
[ 1905 ] 
There are several interesting Sporozoan papers to record ; though 
the Coccidia have been almost neglected. Led by his observation (43) 
of slight anisogamy in the conjugating elements of certain Monocystid 
Gregarines to reinvestigate the common Monocystis itself, Brasil (44) 
finds that the sexual process in this genus is not, as hitherto thought, 
oompletely isogamous, but that distinctions between the male and female 
gametes really exist. On the other hand, SohnitZler (416) confirms 
the results obtained by previous workers, with regard to the complete 
isogamy in Clepsydrina ( Gregarina ) ovata , a Septate form. L£ger (248) 
has discovered a remarkable Gregarine, having its cytoplasm metamerically 
segmented, which he terms Tceniocystis. The investigation of this un- 
doubtedly unicellular animal leads Leger to put forward the interesting 
suggestion that harmonic metamerism may be, in certain cases, the cause 
rather than the expression of repeated (asexual) multiplication (cf. 
Anoplophrya). The occurrence of Haemogregarines in Mammals, described 
by Balfour (7), Christophers (86), and Laveran (227), helps to break 
down still further the division formerly erected between the Hsemosporidia 
of warm- and of cold-blooded Vertebrates. Rogers’ sensational observation 
of Flagellate phases in connection with the extra-corporeal development of 
Piroplasma donovani has been amply corroborated and extended by 
Christophers (85), Leishman & Statham (253) and others ; though, so 
far, no true trypaniform phases have been recognized. Koch (214) gives 
an account of what he thinks are developmental stages of Piroplasma 
canis in the tick, but some of the weird appearances figured are not very 
convincing. Coming to the other sub-class of Sporozoa, the Neosporidia 
(or, as they are better termed, the Endospora), Perez’s notes (341-344) 
on certain new Olugeidce are of considerable importance as regards the 
classification of the Microsporidia ; and Caullery & Mesnil (72) publish a 
detailed account of their researches on the Actinomyxidian, Sphceractino- 
myxon. Hesse (177, 179) has observed a new species of the uncommon 
form Myxocystis , which he finds to be a true Myxosporidian. Lastly, the 
number of Sporozoa incertse sedis is increased by Krassilstschik’s account 
(220 & 221) of Microklossia , which seems to combine to a certain extent 
Ectosporan and Endosporan characters. 
Of numerous papers dealing with the Trypanosomes, Prowazek’s study 
(362) on the life-history of Trypanosoma lewisi is the most important from 
a protozoological standpoint ; the author demonstrates that the life-cycle 
of this well-known Mammalian form agrees with that of the Trypanosomes 
of other Vertebrates so far as investigated up to the present, in possessing 
a true Invertebrate host (a louse, Utematopinus , in this case), in which the 
sexual conjugation is undergone. Foa (141) has continued his — the 
Recorder apologizes if he should write her — researches on unusual 
Flagellates and describes two entirely new types, one, Calonympha , being 
of extremely complicated structure. Miss Robertson’s very useful 
account (379) of the remarkable parasite, Pseudospora volvocis , illustrates 
well to what an extent form-polymorphism may be shewn during different 
periods in the life-history of a given Protozoan. A comprehensive 
description of the morphology and variation of the lorica in the Peridinida 
is given by Entz (122). 
Faur^-Fremiet has again taken a prominent share in the work on the 
Ciliates. In his principal memoir (137) he combines much that he has 
previously written upon the cytology of the Vorticellidce ; and other 
information on the same subject is contained in (128, 131 & 132). In 
(138), it may be noted, this writer gives a full account of the minute 
cvtoplasmic structure of the Rhizopod Cochliopodium. Further papers on 
tne various organellie of Infusoria are those of Gonder (160), Russo & 
di Mauro (389 & 390), Schuberg (419), and Thon (491). 
Some interesting contributions on topics of a more general character 
