THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 113 



polar capsules, by taking accouut of the presence or absence of a vacuole in the 

 plasma, of their number in the [panjsporoblasts, one can, I believe, succeed in 

 obtaining elements suliicient for an attempt of this tind. 



And further : 



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 tlie species that may 

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

 if not to terminate, at least todiminisli 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 whicii I believe adds a serious obstacle to the progress of our knowl- 

 edge in their direction. 



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

 they exi^ress exactly the conchisions at which I had independently 

 arrived. 



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

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

 remaining Mi/xo.sporidia. This primary division (foreshadoAved as early 

 as 1890 by Thclohan) ^ can not, however, 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. Cryptoeystes. 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, Olugeidcv. 



Etymology: -/.fio-TO'^ concealed; x/^orfc, capsule. 



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

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

 symmetry and 2 or more capsules;^ tyjie family, Myxoholidcc. 



Etymology: ^a:Vw, I appear; x^jfrrj?, capsule. 

 Thclohan subdivides the Phcenocystes * thus: 



No vflPiiole • "J or 4 eansiilps f ^ capsules. II. Myxidians. 



JNo\acuoic, wor4capsmes ^ 4 capsules. III. Chloromyxans. 



^ S"^^'"" ''"'^""^'" lor2cap-| ^^ Myxoholam. 



While the structure of the sjioroplasm is of the ntmost importance 

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

 vacuole are undoubtedly its most important taxonomic features, to obtain 



' He says (Anual. de Microgr. ir, p. 205) : 



" It is necessary to distinguish in the Myxosporidia two types of spores; the one of 

 small size, always ovoid, and deprived of polar capsules; these Gluge discovered in 

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

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

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



2 Three asserted in one si>ecies by Leydig (Miiller's Archiv., 1851, p. 229). 



■*Exc('i)t Mi/xohohis unicapsaJatus and M. piriformis. This qualification is omitted 

 by Braun (C<'ntnilh]. f. Bakt. u. Parasitenkde, 1884, xvi, p. 86). 



'For the classification of the Cryptocijuics, see p, lUO. 



F 92 8 



