372 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Adhesion-Cultures.* — P. Lindner describes the following method for 

 examining mixed vegetations in artificial or natural media. A thin layer 

 of the cultivation fluid is spread all over the under side of the cover- 

 glass. The slip is then placed over the hollow of a grouncl-out slide 

 and ringed round with vaselin. 



Should it be desired to cut off or diminish the air-supply to this 

 culture, another cover-slip of slightly less size is put over the film so 

 that the medium is shut in between two glass surfaces. Over the drop 

 culture this method has the special advantage of causing the vegetation 

 to spread out in one plane so that the growth can be readily inspected 

 and photographed. 



(2) Preparing Objects. 



Fixing and Staining Trypanosoma.!— J. R. Bradford and H. G. 

 Plimmer made films by placing a small drop of the infected blood in one 

 corner of a slide or of a slip, spreading it with a piece of goldbeater's 

 skin, held in a pair of forceps. The edge should be quite straight and 

 the width a little less than that of the slip. The best fixative results 

 were obtained from the vapour of a mixture of equal parts of 2 p.c. osmic 

 acid and glacial acetic acid, though 10 parts formalin with 90 parts 

 absolute alcohol give very good results. Fixation by this latter mixture 

 takes 5-10 minutes, after which the film must be well washed and then 

 dried. The stains used were methylen-blue and erythrosin. The 

 methylen-blue was a 1 p.c. M.B. med. pur. (Hochst) to which 0*5 p.c. 

 potassium carbonate was added and the mixture incubated at 87° for 48 

 hours. When cold it is filtered and is then ready for use. The ery- 

 throsin (tetraiodide of fluorescein) was used in 0*001 p.c. solution with 

 0*25 p.c. formalin to prevent growth of moulds. When required for 

 use, 20 ccm. of distilled water are put into each of two beakers, to one of 

 which are added 20 drops of the erythrosin solution, and to the other 6 

 to 8 drops of the methylen-blue solution. The solutions are then mixed 

 and poured into a flat dish in which the slides or slips to be stained have 

 been already placed. In about 20 minutes the preparations are washed 

 in distilled water till no more colour comes away, and are then allowed 

 to dry in the air. No heat must be used for drying, otherwise the red 

 colour will entirely disappear. They are then mounted, preferably in 

 turpentine colophonium. 



Method for Fixing Blood-Preparations. J — Lenoble and Dominici 

 expose the films to the vapour disengaged from a solution composed of 

 perchloride of mercury and iodine, and stain with the Ehrlich triacid 

 mixture. The fixative maybe used in two strengths: — (1) Saturated 

 solution of sublimate in 40 grm. of alcohol to which 6 grm. of tincture 

 of iodine are added. (2) Saturated solution of sublimate in 35 grm. of 

 alcohol and 15 grm. of tincture of iodine. 



Method for Fixing and Staining Haematopoietic Tissue. § — 

 Dominici fixes the material in a medium which has for its basis a mix- 

 ture of alcoholic solution of iodine and aqueous solution of sublimate. 



* Wochenschr. f. Brauerei, xviii. pp. 512-4. See Centralbl. Bakt., 2 t0 Abt., viii. 

 (1902) p. 2S6. t Quart, Jouvn. Micr. Sci., xlv. pp. 449-71 (2 pis.). 



% C.R. Soe. Biol, de Paris, liv. (1902) pp. 223-5. § Tom. cat., pp. 221-3. 



