THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 113 



polar capsules, by taking account of the presence or aliscncc of a vacuole in the 

 plasma, of their number in the [pan]sporoblasts, one can, I believe, succeed in 

 obtaining elements sufficient for an attempt of this kind. 



And fuitlier : 



I do not pretend to give a final classification of these organisms; I have -wished 

 only to furnish a means, a provisional means, for assigning to the species that may 

 be discovered, a place in accord with their affinities; and above all I have wished, 

 if not to terminate, at least to diminisli the confusion which results from the arbi- 

 trary and vague manner in which all species have been designated; a confusion 

 which I have only too often had occasion to recognize since I have stud'ed these 

 parasites, and which I believe adds a serious obstacle to tlie progress of our knowl- 

 edge in their direction. 



Upon the above extracts no criticism is needed. As far as they go 

 they express exactly the conchisions at wliich I had independently 

 arrived. 



In any case, there can be no question as to the propriety of drawing 

 a trenchant line between the "Glngeidians" of Thclohan, and the 

 remammg Myjconpor id ia. Tliis primary division (foreshado^Yed as early 

 as 1891) by Thelohan)^ can not, hoAvever, rest upon so comparatively 

 unimportant a character as the outline of the spore. I have regarded 

 it as of ordinal value, defining the two orders thus : 



I. Gryptocystes. Myxosporidia in which the pansporoblast produces 

 many (at the fewest 8) spores; the last minute, without distinct sym- 

 metry, with a single capsule; type (and only) family, Glugeidce. 



Etymology: xnu-r'h, concealed; zuctzic, capsule. 



II. Pha'iiocystcs. Myxosporidia in which the pansporoblast produces 

 few (at the most 2) spores;' the last relatively large, with distinct 

 symmetry and 5 or more capsules;^ type family, Myxoholidcc. 



Etymology: ^aiVw, I appear; x^Wrj?, capsule. 

 Th^lohan subdivides the Phcenocystes * thus : 



Ko vacuole: 2 or 4 capsule. J ^ capsule. ^ ^^^^^ 



While the structure of the sporoplasm is of the utmost importance 

 and the presence or absence, and tlie micro-chemical reactions of the 

 vacuole are undoubtedly its most important taxonomic features, to obtain 



' Ho says (Annul, de Microgr. n, p. 20")) : 



"It is necessary to distinguish in the Mi/xosporidia two types of spores; the one of 

 small size, always ovoid, and deprived of polar cai)sules; these Glugo discovered in 

 the stickleback. The others, with which the authors have principally occupied 

 themselves, are distinguished by their more considerable size, the different forms 

 which they jjresent, and by the presence of capsules." 



'Three asserted in one species by Leydig (Miiller's Archiv., 1851, p. 229). 



'Except Mi/xoholiis unici(i)Hiil(iliin and .]/. piriformis. This (lualification is omitted 

 by Braun (Ct-ntialbl. f. Hakt. u. Parasitcnkde, 1881, xvi, p. 8G). 



••For the classiticatiou of the Cri/ptoci/vles, see p. 190. 

 F c 92 8 



