THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 93 



Exit of the SPOROrLASM. 



This, tlic last phenomenon of the spore stage, was first observed by 

 LieberkiUin,^ who described the process as seen in Mt/xoholus sp. 65. 

 He also figured it as occurring in M. sj). 44. Gabriel ^ also describes 

 (bat in a somewhat different way, and possibly erroneously) the freeing 

 of the sporoplasm in Myxidium Jiebcrldlhnii. It was also observed by 

 Balbiani^ in Myxoholus ellipsoides, and recently it has been confirmed 

 by Pfeifter* and by Perugia.^ 



Biitschli,'' however, eijtertains some doubt as to the supposed sim- 

 plicity of the life-history based upon these observations. His objections 

 are chiefly that this view leaves no function for the capsules to perform. 

 As indicated above, tliis exit appears only to take place at a (for the 

 capsules) JJOs^/^fMc/^o»^r? period. 



III.— ZOOLOGICAL POSITION. 



Gluge ' regarded the spores of Glugea anomala as crystals modified 

 by an unknown cause. He says: 



It is known from tlie researches of M. Ehrenberg that the silvery color of fishes 

 is produced by a great number of corpuscles of a crystalline structure and a form 

 cylindrical and a little recurved. It appears to me extremely probable, from all 

 that precedes, that the corpuscles contained in the cysts are only the crystals of the 

 normal state, but changed by an unknown cause. 



Miiller'^ regarded the ^ii/xo.sporidia as agreeing neither with the s])er- 

 matozoa nor with the germs of develojiing animals, nor with the tailed 

 Entozoa or Cercaria^, and as deviating equally in structure from the 

 known fungi parasitic upon animals; finally, through their form, struct- 

 ure, development, specific distinctions, and absence of motion, they 

 deviate from all known normal and pathological cell formations. This 

 observer ^ bestowed upon these anomalous forms the name of "psoro- 

 sperms,"^" recalling both the cutaneous ''eruption" produced by them 

 and the resemblance of the tailed spores to spermatozoa. 



The credit of first suggesting a definite zoological position for the 

 subclass is due to Creplin.^' It will be seen that he was the originator 

 of what may be called the " gregarine theory." 



'Muller's Archiv., 1854, p. 354; Bull. Acad. Roy. Belg., 1854, xxi, pt. 2, p. 21. 



2 Jahres-Ber. schles. Ges. vaterl. Cultur f. d. J. 1879, LVii, p. 192. 



3Compt. Rend. Acad. Sci. Paris, 1863, lvii, p. 160. 



•'Die Protozoen als Krankheitserreger, 1890, 1 ed., p. 47; 2 ed., 1891, p. 133. 



•■^Boll. Scientif., Pavia, 1891, xiii, p. 23. 



«Ztschr. f. wiss. Zool., 1881, xxxv, pp.. 637-8; Bronn's Thicr- Reich, 1882, i, i).595. 



7 Bull. Acad. Roy. Belg., 1838, Y, p. 776. 



8 Miiller's Archiv , 1841, pp. 487, 488. 



9 Mile Leclercq (Bull. Soc. Belg. de Microsc, 1890, xvi, p. 100) erroneously attrib- 

 utes the name to Gluge. 



1" Derivation furnished by Balbiani ( Journ. de Microgr., 1883, vii, p. 145) as follows : 

 yjjupa, mange; aKspfza, seed. 



" Wiegm. Archiv. f. Naturgesch., 1842, i, iip. 65, 66. 



