THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 93 



Exit op the Sporoplasm. 



This, tlie last plieiiomenon of the spore stage, was first observed by 

 Lieberkiihn,^ who described the process as seen in Myxoholus sp. 65. 

 He also figured it as occurring in ilf. sjj. 44. Gabriel ^ also describes 

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

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

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

 by Pfeiffer^ and by Perugia.^ 



Butschli,'^ however, entertains some doubt as to the supposed sim- 

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

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

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

 capsules) post-functional period. 



III.— ZOOLOGICAL POSITION. 



Gluge "^ regarded the spores of Glugca anomala as crystals modified 

 by an unknown cause. He says: 



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

 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 j>recedes, that the corpuscles contained in the cysts are only the crystals of the 

 normal state, but changed by an unknown cause. 



Miiller^ regarded the Myxosjjoridia as agreeing neither with the ST)er- 

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

 Entozoa or Cercarue, 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 fornmtions. 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." 



'Mullet'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. 



^Compt. Rend. Acad. Sci. Paris, 1863, i.vii, p. 160. 



■•Die Protozoeu 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. G37-8; Brouu's Thier- Reich, 1882, i, p.595. 



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



sMiiller's Archiv., 1841, pp.487, 488. 



''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 : 

 fcjpa, mange; anep/na, seed. 



11 Wiegm. Archiv. f. Naturgesch., 1842, i, pp. 65, 66. 



