ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 513 



satisfactory being Gilson's fluid, though picro-acetic, chrom-acetic, and 

 picro-eorrosive gave favourable results. Auerbach's methyl-green and 

 acid-fuchsin stain was used for studying cell-contents. Heidenhain's 

 iron-haematoxyliu and Congo-red was found to be most valuable, and 

 eosin-toluidin blue was also successful. 



" (4) Staining' and' Injecting-. 



New Microchemical Tests for Wood.* — Y. Grafe adds to a solution 

 of vanillin some drops of isobutyl-alcohol, and lets a little sulphuric acid 

 (sp. gr. 1 • 84) run down the side of the test tube. After heating, the 

 mixture turns dark-red, with a shade of blue. On diluting with alcohol 

 and repeated additions of acid, it changes through blue-green to pale 

 green. The author recommends as a standard reagent the following : 

 30 c.cm. isobutyl-alcohol plus 15 c.cm. sulphuric acid. When wood- 

 mash is treated with this reagent the wood turns black ; if now diluted 

 with a little alcohol and the test tube be shaken, the wood turns blue or 

 blue-green, while the fluid becomes red- violet. Sections of ligneous tissue 

 treated with this fluid are at first red- violet and after a time blue. The 

 sections should remain in the reagent for about an hour, and then be 

 mounted in glycerin. Apparently the stain is not very permanent. 



A mixture of isobutyl-aldehyd and sulphuric acid also forms a useful 

 reagent. A drop of the mixture placed on a micro-section gradually 

 turns it red, and if after the lapse of about an hour it be placed in 

 glycerin it assumes a wine-red or red-violet hue. 



Demonstrating Fat-Cells in Glandulae Vesiculares of Cattle.f — 

 G. Illing found that the best fixative for demonstrating the fat in the 

 cells of the glandula? vesiculares J was Podwyssozki's fluid (1 p.c. chromic 

 acid 15 c.cm., ^p.c. subHmate 15 c.cm., 2 p.c. osmic acid 4 c.cm., acetic 

 acid 6-8 drops). This showed the fat as black globules. 



The special fat stains, Scharlach E, sudan iii, and indophenol, were 

 also used. For Scharlach R the pieces were fixed for 24 hours in 10 p.c. 

 formalin, and after having been washed in running water for some hours 

 were sectioned with a freezing microtome. The sections having been 

 washed first in water and then in 70 p.c. alcohol, were immersed for 

 2-3 minutes in Herxheimer's solution (absolute alcohol 70, 10 p.c. caustic 

 soda 10, distilled water 10, Scharlach R. to saturation). The sections 

 were then washed in 70 p.c. alcohol, and next after-stained with dilute 

 aqueous hematoxylin solution, toluidin-blue, or methylen-blue. Having 

 been washed with water, they were mounted in lasvulose or in glycerin. 



Studying the Connective-Tissue Framework in Lymphatic 

 Glands.§ — J. Bartel and R. Stein fixed the material in Zenker's fluid 

 and made paraffin sections in the usual way. The sections were first 

 stained with * 1 p.c. aqueous acid fuchsia for 2-3 minutes. After wash- 

 ing in water they were immersed in a 1 p.c. solution of phospho-molybdic 



* Oesterr. Botan. Zeitschr., lv. (1905) p. 174. See also Zeitschr. wiss. Mikrosk., 

 xxii. (1905) pp. 581-2. t See also this Journal, 1905, p. 683. 



+ Arch. Mikrosk. Anat., lxvi. (1905) pp. 121-7 (1 pi.). 

 § Arch. Anat. Phys., 1905, pp. 141-58 (1 pi.). 



