1 74 A PARASITE OF THE REPRODUCTIVE ORGANS OF THE GOLDEN SWAMP FROG. 



In a section of an infested testis a large portion of that organ may be seen to be occupied by cysts. 

 Each cyst is surrounded by a narrow, lightly-staining ring — the ectoplasm. Immediately within 

 this is a denser, more or less granular layer containing developing spores, while within this again the 

 cyst is closely packed with fully-developed spores. In the very small cysts few or no mature spores 

 are distinguished. In sections stained with carbol fuchsin masses of spores may be noticed lying 

 in the seminiferous tubules along with the sperms. 



In a section of an infected oviduct, the cyst was observed to lie between the layers of the wall 

 and to project into the lumen of the duct. It possessed the same structure as described above. 



Stages in Development. — Cells with a single nucleus were fairly common in smears made from a 

 cyst, and perhaps represented the young pansporoblasts. Cells with 2, 4, 6 and 14 nuclei were seen, 

 and were probably stages in the development of the spores within the pansporoblast. Other larger 

 cells, with prominent irregular nuclei and smaller, more deeply staining chromatin masses in the 

 cytoplasm, were also met with. 



<*)© I 



Fig. 5. — Some developmental stages : a, amcebula ; 

 e c n, envelope cell nucleus ; p c, developing 

 polar capsule ; pec, polar capsule cell. 



Experimental. — In April, 191 5, two infected testes were removed from a Golden Swamp Frog, 

 Hyla aarea, and fed to two Green Tree Frogs, H. ccerulea. After three weeks, one was killed, but 

 an examination of it failed to reveal the presence of Myxobolus ; the other frog escaped. In November, 

 iqi 5, cysts from a female H. aurea were fed to another H. carulea. After four weeks the latter seemed 

 sickly and was killed, but no myxosporidia were detected within it. 



The parasite is apparently specific in its associations, since it has not been observed in any frog 

 other than //. aurea. Both H. aurea and H. ccerulea occur around Sydney ; the former abounds in 

 swamps, and is much more common than its larger tree-climbing relative. 



It has already been pointed out by Cleland and Johnston that the latter harbours a blood parasite, 

 LankestereUa hyla, which has never been detected in the Golden Swamp Frog. 



Literature Referred to. 

 1910. Auerbach, M. — Die Cnidosporidien. 



1910. Cleland, J. B., and Johnston, T. H. — The Hsematozoa of Australian Batrachians. Proc. Roj . 



Soc. N.S.W. xliv., 1910, pp. 252-261. . 



191 1. Doflein, F. — Lehrbuch der Protozoenkunde. 



1888. Fletcher, A. W. — On a Myxosporidium Infesting Australian Frogs. Rep. Austr. Assoc. Adv. 

 Science, i., 1888, p. 337. 



