THE MYXOSFOKTDIA, oK l'S()K( )S1"];k'MS OF FISHES. 2G3 



aiiiu'boiil spuroplasiu fioin the spore (see below) causes him to support 

 the opiuions of Lieberkiilm aiul I^>albiaui. Unfortuuately, however, 

 he adds the following: 



Filially, also, the observatiuns of Thi'li)liaii upon tli« faihue of the lilaiiu'iits iu 

 the capsules of many spores is not favoralile to the mode of view of Miugaz/iiii. 



Here again we have tlie ribbonettes and the capsulat' Jilaments con- 

 founded, another instructive warning against the ai)pli(;ation of the same 

 name to two entirely ditterent structures (see also p. 87). 



Perugia further remarks (p. 138) that if the " gregarinoid forms" be 

 regarded as larval stages the adult forius represent a retrogression, 

 inasmuch as the '' gregarinoids'- with a nucleus and the protoplasm 

 regularly disposed, need only a cuticle to be monoc^ystids, while the 

 adult stages, <lestitute of a nucleus and with the protoplasm never 

 regularly disposed, are much farther removed therefrom. Perugia was, 

 howevei-, unable to find any such ''gregarinoid forms." 



Kruse, however, says: 



Very interestiug is au observation of Mingazziiii'a, wliich the author can confirm. 

 In the gall bladder of the Selachians are found, besides typical Mtixospovidht, long- 

 drawn-out, tailed bodies, which move in Gregarine fashion, but which, on the other 

 hand, are connected by manifold transitions with the amoeboid forms. 



Spore toriiiaf ion. — Rapidity of spore foriuation is truly extraordinary, 

 most of the individuals liaving spores fornved or in course of formation 

 in less than lo minutes. At undetermined points in the endoplasm (in 

 the middle or near the ]>eriphery) appear round vacuoles of clear proto- 

 plasm, which, like the ectoplasm, originate by a rai)id transformation 

 of tlie yellow protoplasm. This vacuole presently acquires an envel- 

 oping membrane, and within it is formed the spore. Its theca shows 

 an oblique striatiou in two directions. Spin'es may arise in individuals 

 whose protoplasm is little modified, i. e., almost entirely composed of 

 yellow granules, the spores being then inclosed in a membrane, round 

 in form, formed from the yellow protoplasm, and containing also a col- 

 orless refracting licjuid ; or the spores may form in colorless protoplasm, 

 in this case without the enveloping membrane, the sjxu'es issuing free 

 and floating in the bile. Where, a3 sometimes hap]»ens in the first case, 

 spores form at the periphery, they form, iu growing, a sort of crown 

 around the individual, and the spcn-e is not set free until the enveloping 

 mend>rane is well formed (INIingazzini). 



\orni;ill\ the pansporoblast shows at some portion of its cireum- 

 leienee. a dist j iicily semilunar aggregation of protoplasmic granules. 

 I'nder the iiiHnence of rengents (e. g., osmic and sulphuric acids) the 

 pansp()rol)last membraiu' bursts, discharging its contents, and remaining 

 as a liyalin<! empty sac (Perugia). 



Spore. — Untailed; euneate f)vat«>.; eai)sules 1. Perugia saw the exit 

 of the s]K)roi)lasni IV<»mi a spore of the gall l)!adder of T. narke. The 

 hirge stiia' on the sliell ren<lei tlie posterior border of the shell in ccm- 

 tour dentate (Thelohan, isoi'j see also p. L'tilj. 



