396 
The Sellizogregarines 
though they do not stain in the same manner, are probably derivatives 
of chromatin. Grains of paramylum are also present, scattered in the 
network. Complicated nuclear changes take place during the growth 
both of the schizont and gametocyte. 
There are slight differences in the merozoites formed from the 
two kinds of schizonts. The length of the merozoites averages 1(V to 
lip.; but slight differences occur in the breadth of the two varieties. 
Leger and Duboscq remark that during the course of the development 
in the lymphoid tissue, a large number of young parasites are the prey 
of phagocytes which bring about their degeneration. This waste, together 
with the arrest of some of the sporozoites by the basal membrane, 
accounts for the rarity of cysts reaching maturity in nature. 
Crabs do not feed directly on the stomachs of Sepia under natural 
conditions, but take up the sporocysts while eating the excrement of 
Cephalopods. 
As regards the sporogonic stages of Aggregata in Cephalopods 
(which are initiated by merozoites from Aggregata of the crab), the 
most recent account is that of Moroff, who disagrees—especially in his 
preliminary communication in 1906—with the account given by 
Siedlecki in 1898. In his earlier papers Moroff has especially disputed 
Siedlecki’s account of fertilisation. Moroff considers that the macro- 
gametocyte forms more than one macrogamete, or that “ fertilisation 
occurs at the time of formation of the [primary] sporoblasts,” and that 
fertilisation occurs between anisogamous gametes, as in some Gregarines. 
However, Moroff (1908, p. 119) subsequently recognised that most of his 
earlier figures of fertilisation have nothing to do therewith, but merely 
represent stages in the division of the sporoblast. Moroff’s grounds, then, 
for considering Aggregata as a Gregarine are insufficient (as remarked 
by Caullery in his review, Bull. Inst. Pasteur, vi. p. 723). New 
researches are needed on this important matter, and Siedlecki’s 
descriptions of fertilisation are not yet refuted. 
Moroff forms many new species of Aggregata from the parasites 
observed by him in an Octopus (sp ?) of Cavaliere (Var, Mediterranean). 
The specific differences according to Moroff are based on nuclear 
structure ( e.g. variation of karyosome), or on the size of the gameto- 
cytes. Probably the number of species will ultimately have to be 
reduced. The sporocysts of species of Aggregata in the Octopus contain 
8 to 24 sporozoites. Of the older species, A. eberthi and A. octopiana 
(Schneider) are the chief. Moroff’s paper (1908) is largely written 
from the physiological point of view. 
