H. B. Fantham 
303 
(1875), Mingazzini (1892), Labbe (1896), Siedlecki (1898), and others. 
The work of Siedlecki is especially noteworthy. Species of Eucoccidium 
are known in various cuttlefish and Octopus. The multiplicity of 
species in Cephalopods, and of workers thereon, has led to great 
confusion in the nomenclature. The so-called Coccidian genus was 
variously known as Eucoccidium , Klossia, Benedenia, Legeria, and 
Legerina. 
Leger and Duboscq have now ended the confusion by giving the 
name Aggregata ( Eucoccidium) eberthi to the parasite whose schizogony 
occurs in Portunus depurator at Cette and in Portunus arcuatus at 
Roscoff, with its sporogony in Sepia officinalis. The methods of Leger 
and Duboscq, as before mentioned, were experimental. They fed 
specimens of Portunus on parasitised stomachs of Sepia. These stomachs 
contained sporocysts of A. eberthi. After a period varying from 1^ to 
36 hours in the crab’s stomach, the ripe sporocysts opened by the 
bursting apart of the two valves (Fig. 9, B) and the sporozoites were 
set free in the intestinal juice of the crab. The sporocysts of A. eberthi 
(Fig. 9, A), which are about 9g in diameter, contain three sporozoites 
(Fig. 9, A, B). The free sporozoites are vermicular, curved or 
S-shaped (Fig. 9, B), and have a very slightly enlarged anterior ex¬ 
tremity, with an elongate nucleus about 5g long near the posterior 
end, without a distinct karyosome. The sporozoites average log to 
18/r in length by T8yu, to 2g in breadth. When set free the sporozoites 
rapidly penetrate the epithelial cells of the intestine of the crab. Most 
of them traverse the epithelium and soon attain the basal membrane, 
through which they try to pass. This basal membrane, however, is 
thick and resistant, and many of the sporozoites are stopped by it. 
Some succeed in piercing the basal membrane and gain the peri- 
intestinal lymphoid layer, where their further development takes place. 
The other sporozoites, which are unable to penetrate the basal mem¬ 
brane, remain imprisoned in the crab’s intestinal epithelium, and 
ultimately die; they hypertrophy, become pyriform and degenerate. 
The sporozoites (Fig. 9, C), which have succeeded in reaching the 
lymphoid tissue, remain there and continue their development. For a 
time their primitive length (log to 18 g) is retained, while they increase 
in breadth (from 2 g to 8 g), becoming reniform and then nearly spherical 
(Fig. 9, D). The period of growth lasts about 10 days. During this 
growth in breadth, the nucleus changes in position, in shape and in 
structure. From elongate oval it gradually becomes spherical, and takes 
up a central position in the cytoplasm. The chromatin of the nucleus, 
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