Morphology 547 



soma gambiense discovered in the blood by Forde and Button, and 

 described the newly discovered organism as Trypanosoma ugan- 

 dense. Kruse,* thinking to honor the discoverer, called it Try- 

 panosoma castellani. Bruce and Nabarrof found the new try- 

 panosome in each of 38 cases of sleeping sickness in the cerebro- 

 spinal fluid, and 12 out of 13 times in the blood. These observers 

 also found that 23 out of 28 natives from parts of Uganda where 

 sleeping sickness is endemic had trypanosomes in their blood, while 

 in 117 natives from uninfected areas the blood examination was 

 negative in every case. They also declared that, contrary to what 

 had been stated, there were no appreciable morphologic differences 

 between Trypanosoma gambiense and Trypanosoma ugandense. 

 Button, Todd, and Christy J arrived at the same conclusion. The 

 matter was finally settled by Thomas and Linton§ and Laveran,|| 

 who, by means of animal experiments, determined not only the 

 complete identity of the organisms, but their uniform virulence. 



Early in 1910 J. W. W. Stephens** studied the blood of a rat in- 

 oculated with blood from a patient suffering from sleeping sickness, 

 with which he had become infected in North Eastern Rhodesia, 

 . and observed certain definite morphological differences between the 

 trypanosomes in it, and Trypanosoma gambiense. Later he and 

 Fanthamft studied this organism with great care and came to the 

 conclusion that it was a new and separate species, and gave it the 

 name Trypanosoma rhodesiense. In this they received the support 

 of Mesnil.tt 



Morphology. — (i) Trypanosoma gambiense is a long, slender, 

 spindle-shaped, flagellate micro-organism that measures 17 to 28 m 

 in length and 1.4 to 2 ^ in breadth. From the anterior end (that 

 which moves forward as the organism swims) a whip-like flagellum 

 projects about half the length of the organism. The terminal 

 third of the flagellum is free in most cases. The proximal two- 

 thirds are connected with a band of the body substance, which is 

 continued like a ruffle along one side of the organism to within a 

 short distance of its blunt posterior end, where the flagellum abruptly 

 ends at the blepharoplast. This thin ruffle is known as the un- 

 dulating membrane. By means of the flagellum and the undulat- 

 ing membrane the organism swims rapidly with a wriggling and 

 rotary movement that gives it the name Trypanosome, which means 

 "boring body." 



*"Gesell. f. natur. Heilkunde," 1903. 

 t "Brit. Med. Jour.," Nov. 21, 1903. 



tibid., Jan. 23, 1904, also "Thompson -Yates and Johnson Lab. Reports," 

 1905, V, 6, part I, pp. 1-45. 



§ "Lancet," May 14, 1904, pp. 1337-1340. 

 II Compt.-rendu de I'Acad. des Sciences," 1906, v, 142, p. 1056. 

 ** "British Medical Journal," 1912, 11, 1182. 

 j^ tt "Proceedings of the Royal Society," 1910, Lxxxni, 28, 31; 191 2, lxxxv, 223; 

 Bulletin of the Sleeping-sickness Bureau," 1911-1912, Nos. 33, 38. 

 tt"Brit. Med. Jour.," 1912, 11, 1185. 



