98 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. 



Ill 1881, as the result of an extended study of both Myxosporidia and 

 Gregarines, Biitschli^ expressed his opinion substantially as follows: 



That the relation between the Myxosporidia and .the Gregarines is no very inti- 

 mate one is sliown botli by the structure of the uiyxosporidiuiu and Ijy that of the 

 spore, and also by the mode of spore formation. In the last two respects the Myxoapo- 

 r'ulia can be compared with the Gregarines only in the most general Avay. There are, 

 indeed, some observations (e. g., the dubious one of Clapari-de's on Monocystis capUata 

 Leuck., and that of Gabriel on a Gregarine of Jul as, the latter, however, too incom- 

 plete to serve as a basis for theoretic conclusions) whicli render a nonencysted 

 (perhaps also an endogenous) spore formation in certain Gregarines not improbable. 

 The possession in common of bivalve and tailed spore shells is an unimportant 

 similarity. Above all, we have every right to regard the capsules as a character 

 especially indicative of the Myxosporidia, and of these no gregarine spore has so far 

 shown a trace, the two bodies found by Schneider in the Adelea spore being scarcely 

 to be paralleled with them. 



These conditions [the capsules] of the myxosporidian spore sjieak just as strongly 

 against a close connection between the Myxosporidia and the Myxomycetes, as the 

 spores of the latter possess no structures comparable to the myxosporidian capsule. 

 The pigment found in a few Myxosporidia (Myxidium licberkiihnit, etc.) is not to 

 be compared to that of the Myxomycetfes, as it is not of myxosporidian but of 

 extraneous origin. Naturally, the Myxomycetes, especially in the simplest forms, 

 show in their partly peculiar endogenous sjiore formation a certain similarity to the 

 Myxosporidia, but such a similarity also exists between the Myxomycetes and certain 

 Rhizopoda. Among the latter the Myxosporidia seem to possess some special relation 

 witli the interesting Pelomyxa, inasmuch as the latter possesses a great number of 

 small nuclei, and in addition it is probable that it produces endogenously chlamydo- 

 spores, which, however, show no trace of capsules. Further, in the determination 

 of the systematic position of the Myxosporidia stress should be laid upon the cap- 

 sules. From everything that we know they are comparable only to the thread cells, 

 which latter are exclusively animal structures which recent investigations have 

 shown to be present in the Protozoa. I do not conceal that this criterion, like the 

 other barriers which have again and again been raised between the animal and 

 vegetable kingdoms, may be erected only to be overturned through more penetrating 

 research. 



In 1890 Pfeiffer 2 unites into his family "*S^;om7ieu " the Myxospori- 

 dia, Microsporidia, and Sarcosporidia. He says: 



As a transition to more dangerous parasites are next to be made known the Sarco- 

 sporidia, of which Miescher's tubes in the transversely striped muscles of the warm- 

 blooded animals are already known to physicians, but which are also found exactly 

 similar, only with differently shaped spores, e. g.. in the Hesh of the barbel. 



Spore formation has, he says, no constancy, transitions beiug" found 

 towards more highly developed forms and also toward the lower mem- 

 bers of the Sporozoa. Thus in the tench fully developed forms are 

 found only upon the branchiie and in the air-bladder. In the gall 

 bladder and the cysts on the splenic artery, spore types are found which 

 form, step by step, transitions to the simple pseudonavicellre of the 

 Gregarines and to the structureless ovoids of the microsporidian cysts 

 of Bonihyx, Daphnia, etc., and to the condition observed in coccidian 



1 Ztschr. f. wiss. Zool., xxxv, pp. 648-G50; also Bronii's Thier-Reich, 1882, i, pp. 

 601-603. 



' Die Protozoen als Krankheitscrrcger, 1 ed., pp. 25-27, i'2, 4.8, 74. 



