CHAPTER XII 



TRYPANOSOMES AND ALLIED FORMS 



TECHNICAL SUGGESTIONS 



The most readily available trypanosome for laboratory work is 

 Trypanosoma lewisi from the wild rat. A drop of fresh blood from the 

 tail should be examined under the 4-mm. lens of the microscope, 

 with the diaphragm almost closed. If a considerable number of 

 freshly killed rats is available, transfer 5 to 10 cc. of blood to small 

 vials, defibrinate, and examine promptly on return to the laboratory. 

 In such blood, or in the livers of infected rats kept in a refrigerator, 

 the trypanosomes will persist and be infective for a week or more. 



If an infection is found, inoculate 3 to 5 cc. of the blood into the 

 body cavity of a young white rat, by means of an ordinary hypodermic 

 syringe or even by means of a fine-pointed pipette. The parasites 

 appear in the circulating blood in a day or two and persist for upwards 

 of a month. In order to be sure of maintaining the supply, other 

 young rats should be inoculated at least once a month. 



Detailed technique for the study of the life cycle of Trypanosoma 

 lewisi in the rat flea may be found in the monograph by Minchin and 

 Thompson, 1915. 



Permanent mounts of trypanosomes may be prepared by the dry- 

 film method, staining with Wright's stain. A preferable method is 

 to fix the moist films in hot Schaudinn's fluid and stain in iron 

 hematoxylin. 



Prepared slides of Trypanosoma gambiense are on sale but offer no 

 advantage over those of T. lewisi for general laboratory study. 



Our native frogs are not uncommonly infected by T. rotatorium, but 

 the parasites are rarely abundant. Hegner has called attention to 

 the value of aquatic specimens of the salamander, Diemyctylus 

 iriridescens, as a source of T. diemyctyli. 



Demonstration slides showing the intracellular phases of Trypano- 

 soma cruzi are to be purchased, as are also those of Leishmania. As a 

 representative of species having only an invertebrate host, Herpetom- 

 onas muscce-domesticce is readily obtainable from the intestine of 

 houseflies and various blowflies. 



CHARACTERISTICS OF THE MASTIGOPHORA 



The Mastigophora or Flagellata are Protozoa which are 

 provided with one or several whiplike flagella. The group is a 

 large one and contains many free-living forms as well as numerous 



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