532 SUMMARY OF CURRENT RESEARCHES RELATING TO 



results. If it is desired to counterstain the tissues, the sections should 

 be dipped in Lofrler's methylen-blue solution for a second. The 

 celloidin is removed in the usual way, and the specimen cleared by oil 

 of origanum instead of by xylol, and then mounted in Canada balsam. 



Staining Vegetable Phosphorus Compounds.* — C. Bongiovanni 

 recommends the following methods for detecting organic phosphorus 

 compounds' in plant tissues, and has applied it to the seeds of Ricinus 

 communis, wheat, and Tropseohim mqjus. 



1. Sections of the seeds are warmed gently with dilute hydrochloric 

 acid, washed several times with water, treated with 10 p.c. ferric chloride 

 solution, again washed, immersed in 10 p.c. potassium thiocyanate, and, 

 after further washing, examined under the Microscope, when the 

 globoids are seen to be stained yellow. 



2. The sections are immersed for about fifteen minutes in a saturated 

 solution of molybdic acid in hydrochloric acid and then placed, without 

 washing, in a 10 p.c. stannous chloride solution containing a few drops 

 of 5 p.c. potassium or ammonium thiocyanate solution. In this way the 

 cell-sap is coloured a faint yellow, and the globoids of the aleurone 

 granules an intense reddish-violet, whilst the protoplasm either remains 

 colourless or assumes a faint violet coloration. 



Staining librocartilage.t — B. Lunghetti obtains good contrast 

 results by staining the sections for half-an-hour in the aqueous solution 

 of tropasolin, and then after-washing in 0\2 p.c. methyl-violet for 1 to 5 

 minutes. After another wash the sections are immersed in 10 p.c. 

 acetic acid for 5 minutes. Differentiation is obtained by means of 

 alcohol. The basis is orange and the cells violet. 



Another stain which gives good contrast by metachromatism is 

 thionin, the hyalin substance being red-violet and the fibrous blue. 



New Method of Staining Negri's Corpuscles.} — F. Neri fixes 

 smears with absolute alcohol and sections by Henke and Zellers' method- 

 He then treats the preparations for 10 minutes in iodine-eosin, and after 

 washing in distilled water, counterstains for 5 minutes with 1 per 

 thousand aqueous methylen-blue. The preparations are then washed, 

 dehydrated, and differentiated in 95 p.c. alcohol and mounted in balsam! 

 The composition and preparation of the eosin-mordant are as follows : 

 0-1 grm. of iodin and o-2 grin, potassium iodide are dissolved in a 

 minimum quantity of distilled water, and then the mixture is made up 

 to 50 c.cm. with distilled water. To this is added the eosin solution, made 

 by dissolving 1 grm. of eosin in 50 c.cm. of distilled water. Negri's cor- 

 puscles assume a violet-red hue, and are therefore easily detected. 



Silver-staining of Spirochaeta pallidal— J. Barannikoff fixed and 

 hardened pieces of tissue, 1 c.cm. by 0'5 c.cm., in different fluids e.o\ 



* Staz. Sperim. Agrar. Ital., xlii. (1909) pp, 116-20., See also Journ. Ckera Soc 

 xcv. and xcvi. (1909) p. 512. 



f Zeitschr. wiss. Mikrosk., xxv. (1909) pp. 306-16 (1 pi) 

 % Centralbl. Bakt., lte Abt. Orig., 1. (1909) pp. -109-12 

 § Tom. cit., pp. 263-7. 



