THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 85 
by the occurrence of both in the same species under the influence of 
sulphuric acid. The other reagents which tend to produce filament- 
extrusion are caustic alkalies, hydrochloric and nitric acids, ether, 
glycerin, boiling water, mechanical pressure (e. g., the rolling of a 
mass of spores in an insufficiency of fluid, under the cover-glass), etc. 
As noted by Biitschli,! the extrusion in the latter case is apt to be more 
or less abnormal. 
Concerning filament-extrusion in preserved material, Thélohan? 
says: 
After the action of alcohol upon the spores the filament remains in the capsule 
and it becomes impossible to make it go out. 
While not usual, extrusion does sometimes occur with alcoholic speci- 
mens, a certain (rather small) proportion of the spores emitting their 
filaments under the action both of sulphuric acid and of iodine water, 
In my experience the filaments appear usually not to have much affin- 
ity for stains; the capsule where stained, always shows a markedly 
lighter center. Kolesnikoff, however, found them to stain in Myxobolus 
kolesnikovt. 
HOMOLOGY AND FUNCTION, 
The capsules were first observed by Miiller (see p. 241), who consid- 
ered them the embryos. 
In 1852 Leuckart * regarded these structures as fat globules. He says: 
Also, they [the spores] contain s¢me plain granules of a fatty quality, which are 
distinguished through their constant location in one or both poles. 
In 1863 Balbiani‘ discovered the filament and its capability of extru- 
sion. Regarding the spore as an adult cryptogam, he assigned to the 
filament the role of an antherozoid. 
In 1875 Schneider® remarked that— 
As regards a resemblance between the falciform corpuscles and the polar organs of 
the psorosperms of fishes, it is impossible for me to find it. * * * The falciform 
corpuscles are not such sacks occupied by a slender filament rolled into a spiral. 
Commenting upon Balbiani’s views, Leuckart says:° 
The signification of the elements is unknown, but it may be safely admitted that 
_ Balbiani’s view, which sees therein an antherozoid, is without foundation. Perhaps 
it is to be regarded as an attachment apparatus. 
He further remarks that a comparison of the capsules with the falci- 
form corpuscles is excluded by Lieberkiihn’s and Balbiani’s observations 
of the exit and ameeboid movement of the sporoplasm. 
1Ztschr. f. wiss. Zool., 1881, xxxv, p. 635; see Myxobolus miilleri, p. 219. 
?Annal. de Microgr., 1890, 11, p. 207. 
3 Archiv. f. physiol. Heilkde, x1, pp. 434-5. 
*Compt. Rend. Acad. Sci. Paris, Lvu, p. 159. This discovery has since been con- 
firmed by numerous observers. 
5 Archiv. de Zool. Exper., Paris, 1v, pp. 548-9. Ihave not seen a distinctly asserted 
comparison between the capsules and the falciform corpuscles to which this could 
refer, but such a comparison is implied by Leuckart’s parallelism of Myxidium (?) 
sp. 102 (Archiv. f. physiol. Heilkde, 1852, x1, fig. 21 b) with the'spore from the testicle 
of Lumbricus. 
®Die Parasiten des Menschen, 1879, 2 ed., p. 247. 
>. 
