ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
347 
commences quite early and continues during its development. Like all 
the Sporozoa the Myxosporidia are parasites. 
They have been found in a few Invertebrata and in certain Batrachia, 
but most frequently in fishes. They present themselves under two 
different conditions, as free mobile amoeboid masses, and as more or less 
voluminous cysts. The free form is found usually in natural cavities 
(bladder, renal tubules, liver, spleen, ovary, &c.) while the encysted 
form is most frequently observed in the subcutaneous connective 
tissue, and the subepithelium of the branchiae. 
According to the author, the spores are ovoid or fusiform in shape, 
and of two kinds one is small, ovoid, and without polar capsules ; the 
other is larger, encapsulated, possesses two polar bodies, a mass of proto- 
plasm, a vacuole, and also a nucleus. The capsule, which is extremely 
resistant to reagents, is stainable with safranin, and possesses at its small 
end an aperture that serves for the exit of a filament. 
In technique the author followed the lead of M. Henneguy. The 
best fixatives were found to be Perenyi’s and Flemming’s fluids. The 
paraffin-imbedded sections were fixed to the slide with Mayer’s albu- 
men, and then washed in xylol and absolute alcohol. After this they 
were stained, safranin, borax-carmine, and picrocarmine, followed 
by gentian-violet (Gram’s or Bizzozero’s method), giving the best result. 
Spores, obtained by teasing out, were best treated with osmic acid 
and methyl-green. 
The Genus Didymophyes.^ — Dr. P. Mingazzini maintains the 
inaccuracy of the general opinion which regards Didymophyes as two 
individuals. In the young stage Didymophyes is a single-celled Gregarine, 
and the individual which unites with another posteriorly loses its indi- 
viduality and becomes simply a metamere. In the union, the head is lost 
by fusion with the deutomerite. Encystation is preceded by a shortening 
and broadening of the conjugated cells, and the cysts show no nucleus. 
* Atti R. Accad. Lincei — Rend., v. (1880) pp. 365-8 (4 figs.). 
