50 Prof. 
XVIII. PROTOZOA. 
Complete life-cycle of Plasmodium vivax , Schaudinn (336).—In the life- 
cycle of the malarial parasite, Grassi (144) disputes Schaudinn’s state¬ 
ment that the “ookinete” penetrating into the gut-wall of the mosquito 
secretes a cyst; the enclosing cyst being rather solely a product of the host. 
Contrasting the further development of the oocyst in Coccidia with what 
takes place here, where the sporoblasts do not become completely separated 
from one another, he proposes the term “ sporoblastoids ” for these bodies 
in the malarial parasite. 
Hintze’s (159) chief ground for believing that cysts in the hinder part of 
the frog’s gut were those of Lankesterella , was because of the absence of 
sporocysts. But only very young cysts were seen, and the formation of 
sporoblasts and sporozoites not observed. As Lithe in the Zool. Centrlbl. 
abstr. surmised, it was quite likely that the author had been mistaken, and 
Schaudinn (Arch. f. Protistenk. ii, p. 340) has recently admitted it. 
Crithidia fasciculata , from the intestine of A nopheles rnaculipennis , may 
represent a certain stage in the life-cycle of one of the Flagellates parasitic 
in Vertebrates, LIcger (213). 
Probable life-cycle of Trypanosoma brucei , Bradford & Plimmer 
( 40); in the life-cycle of T. brucei , Laveran & Mesnil (197) have only 
observed longitudinal fission as a mode of multiplication, and do not admit 
a “conjugation.” [Nor do they appear to have seen any multiple fission 
in this species,—a difference from T. lewisi and T. equinum .] 
The life-cycle of Paramcecium , experiments on ; the degeneration- 
tendency can be overcome, and the depression-periods successfully passed, 
by artificial means, without having recourse to conjugation: over five 
hundred generations were thus obtained by “artificial parthenogenesis” 
[See ii, b, 2], Calkins (50). 
E. Evolution ; Group Relationships and Classificatory 
changes. 
Doflein (87 & 88) arranges the Protozoa in two divisions, Plasmodroma , 
forms with pseudopodia or flagella as motile organs, and Ciliophora , forms 
with cilia at one period of life or another. The author holds that these 
two are sharply marked off from each other, but entirely leaves out of 
account Monomastix which so strikingly unites Ciliate and Flagellate 
characters (see below). This leads to the grouping together of the classes 
Rhizopods, Sporozoa, and Flagellates on the one hand, and the Ciliates 
and Acinetarians on the other. Why the allied Ciliates and Acinetarians 
are raised to the dignity of classes, while Mycetozoa, Radiolaria, Fora- 
minifera, etc. are placed together as orders, the Recorder could not gather. 
A much more natural attempt at classifying the group is that of 
Haller (150) who lays stress on the differentiation into flagellated and 
ciliated types, of the simple amoeboid forms of Rhizopods, and traces the 
gradual evolution of the former from the latter. The following are 
suggested as different grades or levels, (1) Ameebce , (2) Mastigamcebce , 
(3) Mastigociliata (including Monomastix and Mallomonas ), (4) Rhizopods 
(from 1), (5) Sporozoa, (6) Flagellates (from 2), and (7) Infusoria (from 3). 
Schubert (347) “sees in the multiform types (‘mischtypen’) of Fora- 
minifera, transition-forms, which are the expression of certain directions of 
development; and in this manner, that.the embryonic chambers point 
to the ancestral condition, while the later-formed ones, on the other hand, 
indicate the ultimate arrangement characterizing the form in question. 
This direction of development may be either leading from a lower to a 
higher type of organisation, or the reverse.”—From a consideration of the 
“ coil-variations ” in the primary part of biformed shells in the genus 
Textularia , Schubert (345) concludes that it is “ not a natural genus, but 
