1912.] On the Extrusion of Granules by Trypanosomes. 387 



becomes more visible, and increases in amount ; the nuclear material becomes 

 differentiated from it and more concentrated, and then we are able to see 

 early forms with a macronucleus and micronucleus. The macronucleus 

 in the circular forms may be spherical or may become elongated and spread 

 out along the periphery. Some forms show much more protoplasm : it stains 

 a pale blue and sometimes shows some faint pink granules. The flagellum 

 varies in length, but is relatively much longer than that of the adult 

 trypanosome. In the internal organs, and especially in the lung, there may 

 be enormous numbers of these small rounded bodies with macro- and micro- 

 nuclei, with or without flagella, sometimes separate and sometimes massed 

 together. 



A further stage has been observed in these masses ; they have been seen 

 just on the point of disruption, some of the small bodies were separating, 

 and lay at varying distances from the main mass. Each showed the two 

 nuclear elements with a small body of homogeneous cytoplasm. 



In addition, forms such as mentioned on p. 385 have been seen — large 

 masses of protoplasm with two, four, or eight macronuclei, and corresponding 

 micronuclei, which ell'©, £LS £1 rule, placed close to the macronuclei. and stain 

 very densely. The flagellum can be seen arising from a line equal in length 

 and close to the micronucleus, in a fan-shaped collection of very fine filaments 

 which unite to form a flagellum (Plate 11). 



In smears of blood or organs advanced single forms — i.e. with one macro- 

 nucleus, micronucleus and flagellum, and a relatively large amount of 

 protoplasm — can be seen, and all stages from this to the adult trypanosome 

 (Plate 11). A series has been prepared showing an almost imperceptible 

 gradation from the granule stage up to adult trypanosomes. 



Up to this point we have only referred to the work of Bradford and 

 Plimmer in their paper on Trypanosoma brucei and its development. In this 

 paper and in the plates they have described and figured the granules within 

 the trypanosomes, the free early bodies, the more advanced single forms called 

 " amoeboid " and the disrupted schizogonous bodies called " plasmodial masses." 



Our work was carried out at a time when we had no access to the paper, 

 and this makes it all the more remarkable that the forms we describe should 

 so closely resemble, and indeed confirm, many of the appearances described in 

 1902, and we feel that in many respects we can add little to the original work, 

 beyond demonstrating the vital properties of these bodies. 



We should like to draw attention to the fact that early granules, forms 

 with short flagella and small round forms, are figured by Mott* in his 



* 'Beports of the Sleeping Sickness Commission of the Koyal Society,' No. VII 

 December, 1906. 



