92 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. 
SPOROPLASM 
This was noted (but apparently regarded as a third capsule) by Miil- 
ler,' and it appears inseveral of his figures. Subsequently Lieberkiihn? 
observed its exit from the spore and its amceboid movements. He also 
notes its visibility within the spore.* These observations have been 
confirmed by Balbiani* and later by others (see pp. 263, 287). 
The sporoplasm is extremely transparent, more or less granular, and 
contains nuclei (1 or more), sometimes a vacuole, and, at any rate in 
the genus Myxobolus, a variable number of brightly refringent granules. 
Nuclei.—These were firstdemonstrated by Thélohan.’ Their number 
is variable in the same spore, according to the stage of development. 
In Myzxobolus ellipsoides, Thélohan demonstrated their origin by contin- 
uous division from a primitive single one. He further says® that all 
species studied by him (with the possible exception of the Glugea species, 
in which the small size of the spore prevented accurate determination) 
have shown 2 nuclei. This accords with my own observations. 
Granules (‘‘refringent globules,” etc.).—These have been noticed in 
several Myxobolus species. They are described under that genus (see 
p. 209). 
Vacuole.—This structure is of two types: (1) The noniodine-staining 
(aniodinophile) vacuole. This is known only in, and forms a marked 
characteristic of, the Cryptocystes. It is situated in the large extremity 
of the ovoid or pyriform spores and is unaffected by iodine. This 
structure was first observed, but not at that time recognized as a 
vacuole, by Thélohan.?. Subsequently he recognized its true nature.® 
(2) The iodine-staining (iodinophile) vacuole. This is known only in, 
and forms a marked characteristic of, the Myxobolide. Itis stained by 
iodine dark brown against a light yellow-brown ground. This reaction 
is best obtained with a dilute solution (aqueous, with potassium iodide). 
Further details are given under Myxobolus (p. 208). 
1 Miiller’s Archiv., 1841, p. 484, pl. 16, fig.3 7, k; ef. fig. 5. 
2Miiller’s Archiv., 1854, pp. 355-4, pl. 14, figs. 7, 8. 
3 Bull. Acad. Roy. Belg., 1854, xxi, pt. 2, p. 21. 
4Compt. Rend. Acad. Sci. Paris, 1863, Lvm, p. 160. 
5’ Compt. Rend. Acad. Sci. Paris, 1889, crx, pp. 920-21. For Perugia’s confirmation, 
see Myxobolus? merlucit (p. 242). For Biitschli’s ‘‘nucleus”, see p. 219. 
6 Compt. Rend. Acad. Sci. Paris, 1892, cxv, p. 1092. 
7Annal. de Microgr., 1890, 11, p. 211, pl. 1, fig. 17a, b. 
8 Relatiye to the homology of the vacuole, Thélohan says: 
‘Is there any connection between the central vesicle and the rest of segmentation 
of the other Sporozoa? <A certain fact is that the aspect of the plasmic mass of the 
spores of the Myxosporidia with that vesicle refractory to staining, and the nuclei 
disseminated in the protoplasm, recalls in a striking manner certain phases of devel- 
opment of the spores of the Gregarines.” 
tl ie ee 
