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very different. Small isolated individuals containing few nuclei are 

 sometimes found surrounded by thick layers of multinucleate connective 

 tissue. Round larger aggregations of multinucleate trophozoites only 

 an insignificant growth of connective tissue is to be observed, and round 

 the larger cysts the connective tissue is paiicinucleate. On the 

 spots where spores are diffusedly spread between the connective 

 tissue frequently multinucleate giant-cells are found. They contain 

 2- -15 nuclei and obtain a dimension of 28 — 43 ft. 



Sometimes a large cyst is found surrounded by many smaller 

 cysts; this phenomenon is most likely to be regarded as a secondary 

 infection, of which the large cyst is the primarj' seat. 



It is a pleasant duty for me to pay my sincere thanks to Dr. Kerbert, 

 Director of the "Kon. Zool. (Jen. "JS'atura Artis Magistra", for his 

 kindness of placing the material for this investigation at my disposal. 



EXPLANATION OF THE FIGURES. 



Fig. 1. Trophozoites in diffused infillration (iiuelei of connective tissue between the 



parasites). 

 Fig. "2. The trophozoites unite into small aggregations. 

 Fig. 3. Encystment of small aggregations of trophozoites. 

 Fig. 4, Pansporoblasts divide into sporoblasls. 

 Fig. 5. Small cysts with sporoblasls, pansporoblasts and spores. 

 Fig. 6. Periphery of a large cyst with sporoblasts and spores (in figs. 5 and 6 



only the circumferences of the spores are sketched). 



Fig. 7. Ripe spores. 



The figures have been drawn with Zeiss's camera : fig. 1 — 6 with oil 

 immersion 2 m.m. ocul. 4 ; fig. 7 with ocul. 18. 



LITERATURE CITED. 



AuERBACH (1910). Die Guidosporidien. Leipzig, VV. Klinkhardt. 



MiNCHiN (1903). Sporozoa. Ray Lankester's treatise on zoology. Part 1 fasc. II. 

 p. 297. 



Thélohan (1895). Recherches sur les myxosporidies. Bulletin scientifique de la 

 France et de la Belgique Vol XXVI. p. 100. 



