and Laboratory Methods. 1305 



1 c. c. of formalin. Stain one to three minutes in the following mixture : satu- 

 rated alcoholic solution thionin, '20 c. c, "JO per cent, carbolic acid, 100 c. c. 

 The fixing solution must be fresh, and the staining fluid at least one week old. 



Nocht's modification of Romanowsky's method consists in the addition of a 

 few drops of neutralized Unna's polychrome methylen blue (Griibler) to the 1 per 

 cent, solution of ordinary methylen blue. The author obtained uniformly good 

 results by the following procedure : (1) To 1 oz. of polychrome methylen blue 

 (Griibler) add 5 drops of 3 per cent, solution of acetic acid (U. S. P. 33 per cent). 

 (2) Make a saturated (1 per cent.) watery solution of methylen blue, preferably 

 Ehrlich's rect. (Griibler), or Koch's, dissolving the dye by gentle heat. This 

 solution improves by age, and should be at least one week old. (3) Make a 

 1 per cent, solution in water of Griibler's aqueous eosin. The mixture is prepared 

 as follows : To 10 c. c. of water add 4 drops of the eosin solution, 6 drops of the 

 neutralized polychrome methylen blue, and '2 drops of 1 per cent, methylen blue, 

 mixing well. The specimens, fixed in alcohol or by heat, are immersed for two 

 hours, specimen side down, and will not overstain in 24 hours. The red 

 corpuscles are stained light pink, the body of the parasite blue, while the chro- 

 matin particles of the nucleus appear deep red. 



Nocht's procedure is also of value in studying the nuclear structures in other 

 micro-organisms. 



Goldhorn (N. Y. Path. Soc, Feb. 13, 1901) has succeeded in increasing the 

 amount of the red staining principle by digesting polychrome methylen blue with 

 lithium carbonate. He stains the specimen for a few seconds in n.l per cent, 

 watery solution of eosin, then in digested polychrome blue 30 to t50 seconds. 



Ewing found no evidence for the view that there is more than one species of 

 the aestivo-autumnal parasite. The nucleus of the malarial parasite belongs to 

 the " distributed type " of protozoan nuclei, consisting of granules of chromatin. 

 While not a true nucleus in the metazoan sense, it possesses all the nuclear 

 structures required in some protozoa. He believes that conjugation of malarial 

 parasites occurs. His observations seem to him to admit of no other explana- 

 tion ; but he does not regard conjugation as an essential feature of the growth of 

 the parasite. He regards the existence of several species of malarial parasites 

 as not yet proven, and adheres to the theory that there is a single polymorphous 

 species. j. h. p. 



Rosenberger, R. C. A New Blood Stain. Phil- Rosenberger discovered that phloxin 

 adelphia Medical Journal, 7: 448, 1 90 1. stains the granules of the leucocytes 



remarkably well. He recommends the following solution as a differential stain 

 for the cells in the blood : 



Saturated aqueous solution of methylen blue, - - 5 parts 

 Saturated aqueous solution of phloxin, - - - 2 parts 



Alcohol (95 per cent.), ----- 3 parts 



Distilled water, -------- 6 parts 



These are mixed together. A precipitate generally forms. The stain should 

 be well shaken before using. It works well after fixation by heat, alcohol and 

 ether, or absolute alcohol. Stain one to four minutes, wash freely, dry, mount 

 in balsam. j. h. p. 



