390 Major W. B. Fry and Captain H. S. Eanken. [Dec. 23, 



methods. The nucleus shows as clearly as, if not clearer than, when 

 Flemming's solution and iron-hsematoxylin have been used. There is the clear 

 space containing the karyosome, and surrounding this, in many cases, are seen a 

 number of granules, some of which can be seen budding off. The blepharoplast 

 is clearly seen as a structure quite distinct from the micronucleus, and the 

 earlier stages of division of a trypanosome, i.e. the division of the blepharoplast 

 and the formation of a second undulating membrane extending down the body 

 of the trypanosome and forming eventually a second flagellum, can be seen 

 and followed easier than with any other mode of fixation. For the smaller 

 forms found in spleen, glands, and marrow of animals with chronic trypano- 

 somiasis, this method, by causing swelling of the elements, renders the very 

 small forms distinct, and renders their nuclear structures much more visible. 



Both these methods are also the best I have found for avian and reptilian 

 blood containing parasites, e.g. filaria, malaria, hcemogregarines, etc. 



The steps of the two methods are here detailed. Either slides or cover- 

 glasses can be used, but in all blood-work the best results are obtained 

 with cover-glasses. After the Giemsa or fuchsin staining the definition is 

 greatly increased by the use of a green monochromatic screen, such as 

 Wratten's No. 19, which shows the picture in blacks and greys. 



I. Vapour Method. 



1. Expose the thinnest possible film whilst wet to the vapour of a solution of iodine in 

 chloroform for 10-15 seconds until it is distinctly yellowish. 



A hollowed glass block does for cover-glasses, and a glass cylinder of suitable height, 

 with the iodine and chloroform in a small vessel at the bottom, does for the slides. In 

 cold places the vessel should be warmed in order to get the vapour given off freely. 



2. Place the film when it has become just surface dry (a dead, mat surface, not really 

 dry) in chloroform, or in alcohol and ether, equal parts, for two hours. I use chloroform 

 for cover-glasses and alcohol-ether for the rougher slides. 



3. There will now be no free iodine left in the film, and it can be stained in many 

 ways. I use the following : — 



A. a. Drop 3-8 drops of Giemsa's solution on the film, and immediately after double 



the number of drops of distilled water. Leave for from 2 to 12 hours. 



b. Wash well with tap-water. 



c. Drop on 2-8 drops of orange-tannin solution and leave for 15 seconds. 



d. "Wash thoroughly with tap-water, up to two minutes. 



e. Dry with filter-paper. 



/. Mount in cedar oil or liquid paraffin. 



B. a. Carbol-fuchsin for from 2 to 12 hours. 



b. Wash in tap-water. 



c. Alcohol until free from bulk of stain. 



d. Differentiate in clove oil saturated with orange G. 



e. Stop when desired by washing in xylol. 

 /. Mount in cedar oil or liquid paraffin. 



