1912.] On the Extrusion of Granules by Trypanosomes. 



391 



C. Iron-hfematoxylin may be used in any of the ordinary ways. 

 Kernschwarz for 24 hours gives very delicate results. 



II. Solution, Method. 



1. Make a saturated solution of potassium iodide in 0'8-per-cent. salt solution and add 

 iodine to saturation. 



2. Mix 5-6 drops of this with 10 c.c. of salt solution. 



3. Mix in a marked pipette equal parts of this and the blood to be examined. In the 

 case of organs small pieces may be crushed in an equivalent quantity of the iodine 

 solution to form an emulsion. 



4. Take large drops and make a thickish film. Wait until the surface has begun to 

 dry (as in I), and place in alcohol and ether for two hours. 



5. Continue as under 3. 



DESCRIPTION OF PLATES. 

 Plate 9. 



Fig. 1. — Series to illustrate mechanism of extrusion of granules in T. nanum (see p. 380). 

 „ 2. — Developmental forms of T. nanum, seen in bone-marrow : the progressive 

 tendency towards the characteristic shape of the adult trypanosome is shown. 

 Dark-ground illumination, Leitz objective, N.A. 1.30, compensating eye- 

 piece, x 8. 



The earliest form, A, shows no evidence of a protoplasmic envelope and has 

 the appearance of a well-developed granule just after extrusion. In B the 

 cytoplasm is clearly evident and the separation of the micronucleus has 

 commenced. C shows a well-developed form, of circular shape, with the nuclei 

 shown at a distance from each other. 



D, E, F, and G show the progressive increase of protoplasm, the last form 

 being almost trypan osornal. H is a young trypanosome, and I an older one 

 in which a flagellum is evident. 



These forms were all living when drawn. 



Plates 10 a>"d 11. 



All the figures are drawn under a Zeiss 3-mm. apo chromatic objective, N.A. 1.40, with 

 compensating ocular. xl2. 



Plate 10. 



Figs. 1-8. — T. rhodesiense in rat's blood, showing granules from their origin to 

 extrusion. 



Figs. 9-16. — From blood and liver of rat infected with T. rhodesiense. 



Figs. 17-22, 24, and 26. — Are from the spleen of a guinea-pig infected with Nagana 

 which lived three months, and showed no trypanosomes in the blood for some time before 

 death. 



Figs. 23 and 25. — From a lymphatic gland of a cat infected with Nagana. 



Fig. 1. — Four granules are seen in the trypanosome-body, and another is in an early stage 

 of being budded off from the macronucleus at the right upper angle. 

 ,, 2. — Two granules are seen coming off the macronucleus. The one on the left is still 

 attached and shows the elongated form. 



