[Proc. Roy. Soc. Victoria, 23 (N.S.), Pt H., 1911.] 



Aht. XXXVllI. — Protozoa Parasitic in tJte Large 

 Intestine of Australian Froys^, Part I. 



By JANET AV. RAFF, B.Sc. 



(Government Research Bursar in the Biological Laboratory, 

 Melbourne University). 



(With Plates XCIV.-XCV.). 



[Read 8th December, 1910]. 



The following investigation was carried out at the suggestion 

 of Professor Spencer, whom I wish to thank for his help and 

 advice. It is an endeavour to record the different protozoa 

 parasitic in the large intestine of our Australian Frogs, and 

 to see how they compare with those in European species. So 

 far I have obtained for examination only five species — viz., 

 Hyla aurea, H. evingii, H. pernnii, TAinnodynastes dorsaJis 

 and L. taswkJxiiiensk, but I hope before long to have other 

 species for investigation. 



In examining the contents of the large intestine I have fol- 

 lowed largely the methods employed by Dobell (4, 5, 6, 7, 8) in 

 his papei's on the protozoa parasitic in European forms. The 

 contents have been kept in a 0.5 per cent, salt solution con- 

 taining egg all)\unen and I have thus been able to keep the 

 protozoa alive for several day.s. For fixing I have used chiefly 

 Schaudinn's corrosive sublimate (hot), and for staining Heiden- 

 hain's iron haematoxylin with or without eosin, picro-c;irmine, 

 acetic acid alum carmine, and acid Kaematoxylin. 



I will now proceed to enumerate the different forms of 

 protozoa present. 



A. CiLIATA. 



Two forms that I have always found to be very abundant 

 in the intestine are S yctotherua and OpaUna. These are 

 present in varying proportions in the different frogs, but gene- 



