TRYPANOSOMA GAMBIENSE 



73 



Morphology of T. gambiense in the Circulating Blood. 



T. gambiense varies from 13 //, to 36 /JL in length, its average length 

 being 24*8 //, as was determined in 1913 by exact biometrical methods 

 by Stephens and Fantham. 1 Three forms of parasite occur. According 

 to Miss Robertson, 2 the relatively 

 short forms from 13 //, to 21 p 

 long may be regarded as the 

 mature or "adult" type of parasite 

 in the blood. They carry on the 

 cycle in the vertebrate. From 

 them intermediate forms, which 

 are longer than the " adult " but 

 at first have the same breadth, 

 arise by growth. They possess 



FIG. 28. Trypanosoma gambiense. 

 (After Button.) 



x 1,700. 



a free flagellum. The intermedi- 

 ate forms grow into long indi- 

 viduals, which are those about to 

 divide. The products of division give rise, directly or indirectly, to 

 the adult forms. 



The organism has an elongate body with an anterior or flagellar 

 end and a blunter posterior or non-flagellar end. The protoplasm 



FIG. 29. Trypanosoma gambiense. Development in vertebrate host. #, long, slender, 

 3, intermediate and c, short, stumpy forms, found in the blood; d, e, f t non-flagellate, latent 

 forms from internal organs. x 2,000. (Original. From preparations by Fantham.) 



is finely granular, large inclusions being rare. The central nucleus is 

 oval and large, often containing most of its chromatin concentrated as 

 a karyosome, with small granules only scattered near or on the fine 

 nuclear membrane. The blepharoplast is either rounded or rod- 



1 Annals Trop. Med. and ParasitoL, vii, p. 27. - Phil. Trans., B (1913), cciii, pp. 161-184. 



