502 SUMMARY OF CURRENT RESEARCHES RELATING TO 



solution of acid-fuchsin (Weigert's) for 1-24 hours. After washing 

 in water they are differentiated in alcoholic solution of caustic potash. 

 The decoloration is continued until the grey substance becomes clearly 

 visible, after which the sections are washed in water, dehydrated, cleared 

 in xylol, and mounted in balsam. The axis-cylinders of the degenerated 

 fibres are clearly traceable by their dark red colour, while the healthy 

 fibres are almost unstained. 



The author's results differ somewhat from those obtained by Hoven, 

 possibly owing to slight differences in the composition of the pigments 

 employed. 



New Method of Flagella Staining.* — A. J. Kendall describes the 

 following procedure for staining flagella. The bacteria are properly 

 diluted on the cover-glass by adding to a tube containing 5 ccm. of sterile 

 water enough of an 18-24 hours agar culture to produce a faint tur- 

 bidity in the upper half of the water. The tube is then placed in an 

 incubator run at the optimum temperature for the particular species for 

 one hour. Two or three drops are then placed on a cover-glass and 

 allowed to dry spontaneously at the temperature of incubator. The film 

 is fixed in the flame and stained by Pitfield's method. Pitfield's mordant 

 consists of 10 p.c. aqueous solution of tannic acid 10 ccm., saturated 

 aqueous solution of corrosive sublimate 5 ccm., saturated aqueous solution 

 of alum 5 ccm., carbol fuchsin 5 ccm. The stain is composed of satu- 

 rated aqueous solution of alum 10 ccm., saturated aqueous solution of 

 gentian-violet 2 ccm. The film is hot-mordanted for about a minute, 

 after which it is washed, then hot-stained, dried, and mounted. 



Staining Mast-Cells and the Chromatin of Malaria Parasites.f 

 — L. B. Goldhorn gives three methods for staining mast-cells. (1) 

 Saturate wood-alcohol with dahlia or methylen-blue and pour the 

 solution on a freshly made blood-smear without previous fixation. (2) 

 Methylen-blue is rendered polychrome and then acidulated with glacial 

 acetic acid. The polychrome solution is made by dissolving 4 grm. of 

 the pigment and 4 grm. of lithium carbonate in 300 ccm. of warm water 

 and heating for 15 minutes in a water-bath. The solution is poured into 

 a bottle and after a lapse of several days is rendered faintly alkaline by 

 adding some 4-5 p.c. acetic acid. Next add 5 p.c. eosin solution, and 

 then filter. Dry the mass on filter in a hot-air oven, and then dissolve in 

 wood-alcohol. (3) Saturate wood-alcohol with methylen-blue, and stain 

 the film for about 15 seconds. Wash in water, and stain in 0*1 p.c. 

 aqueous eosin for from 15 to 30 seconds. 



The author also gives a method for staining the malaria parasite. 

 Dry the films and fix m methyl-alcohol for 15 seconds, wash. Stain in 

 0*1-0 - 2 p.c. aqueous solution of eosin for 7-30 seconds, wash. Stain in 

 polychrome methylen-blue solution for 30 seconds to 2 minutes, wash 

 thoroughly. Dry in air. 



(6) Miscellaneous. 



Improved Method of Making Collodion Sacs.J — N. M. Harris de- 

 scribes a method of making collodion sacs which is an improvement on 



* Journ. App. Micr., v. (1902) p. 183G. t Tom. cit., pp. 1635 and 1S67. 

 X Bull. Johns Hopkins He sp., xiii. (1902) pp. 112-5 (3 tigs.). 



