335] STUDIES ON MYXOSPORIDIA—KUDO 97 



any enclosure except the nuclei and various stages of spore formation 

 (Figs. 161, 165, 168 to 171), the alveolar network being smaller at the 

 periphery than in the center. The ectoplasm is a hyaline, transparent and 

 homogeneous layer, free from any course granulation in fresh conditions. 

 It shows, however, a very fine reticular structure in stained preparations. 

 The pseudopodia are of two kinds in form, always, formed of ectoplasm 

 alone: the filose and bristle-like form, sometimes branching and protruding 

 from the entire surface or from a localized part of the body, vary in length 

 from 0.5 to 4/x according to the size of the individual (Figs. 159, 161, 164). 

 This form developed, sometimes, into a thicker form with two to four 

 branched finer processes. The blunt, lobose pseudopodium formed at a 

 localized part of the body is well recognizable in larger individuals. Fre- 

 quently the filose and the lobose pseudopodia are formed on a trophozoite 

 at the same time. The movements of the blunt pseudopodia were striking 

 in some specimens. At the beginning of the observation, ten minues after 

 the bile was removed from the host, two club-shaped pseudopodia (Figs. 

 161 to 163) which were extruded from a trophozoite, the largest diameter of 

 which being 20ju, moved very actively in the semicircular area changing their 

 forms, showing maximum length of 20/i. In about thirty minutes, they 

 were retracted and from the same place, a short, oval-shaped pseudopodium 

 was seen to be extruded, which remained in the same position for some 

 time without great change of form (Fig. 164). In another case, a tropho- 

 zoite with a very broad and rounded pseudopodium extruded actively two 

 to three rounded smaller processes at its extremity (Figs. 165 to 167). 

 After fifteen minutes the pseudopodium was retracted, the ectoplasm 

 forming a uniformly thick layer around the endoplasm. The observations 

 were done at room temperature in hanging drop preparations, sealed with 

 vaseline and paraffin, by using comp. oc. 12 and apo. imm. ob. 2mm., 

 which caused no mechanical pressure upon the parasites. The change of 

 form and especially that of pseudopodia, was clearly observed for one hour 

 and twenty minutes under the above mentioned conditions after the bile 

 was removed from the host. The trophozoites when kept for sixteen hours 

 at room temperature, underwent degeneration and disintegrated, setting 

 free the spores which were formed in them. 



No active multiplication by plasmotomy, was observed in vivo. In 

 fixed preprations, however, forms that suggested the occurrence of the pro- 

 cess in the present myxosporidian, were recognized. As was stated before, 

 the pseudopodia are always formed of the ectoplasm and as each portion 

 of these dividing forms has many nuclei, the author is inclined to record 

 the presence of plasmotomy in the present form. 



Size varies greatly. The monosporous form 10/jt by 14ju, disporous 

 15/1 by 25/x and polysporous SOju by 50ju, the largest individual, developing 

 and containing more than 200 spores, was 300/x by 50)u. 



