ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 119 



chloric acid 1 c.cm. ; 4 p.c. aqueous solution of copper acetate 1 can. ; 

 water 95 c.cm. After an immersion of from 24 to 48 hours the pieces 

 are removed to a mixture of equal parts of alcohol and distilled, and, if 

 necessary, afterwards to running water. Dehydration in absolute alcohol 

 (24 hours) ; aceton 24 hours ; paraffin 6 to 8 hours. Sections are stuck 

 on with 0*1 p.c. gelatin with a few drops of formalin added. 



Staining- the Internal Network in Nerve-cells.* — R. Collin and 

 M. Lucien fixed the material in the following mixture : 20 p.c. formalin 

 30 ; 1 p.c. solution of arsenious acid 30 ; % p.c. alcohol 30. After 6 to 8 

 hours the pieces are transferred to ^ p.c. silver nitrate solution for 13 

 hours to a few days. After a wash in distilled water they are immersed 

 in the following mixture : hydroquinone 20, anhydrous sulphate of 

 sodium 5, formalin 50, distilled water 1000. The pieces are next washed, 

 hardened, and embedded preferably in celloidin. The sections are then 

 gold-stained by means of the following solutions, mixed immediately 

 before use. A. Hyposulphite of sodium 30, ammonium sulphocyanate 

 30, distilled water 1000. B. Gold chloride 1, distilled water 100. In 

 this the sections remain until they assume a grey hue. Though the 

 following steps are not indispensable, they bring out the network better. 

 After washing in distilled water the sections are treated with the 

 following mixture : potassium permanganate 0*5, sulphuric acid 1, dis- 

 tilled water 1000. Then wash thoroughly in 1 p.c. oxalic acid and 

 afterwards in distilled water. Stain in carmalum, wash, dehydrate, and 

 clear up. 



New Methods of Demonstrating Plasmodes.f — S. Balint fixed the 

 material in 2 p.c. formalin and then cut sections, which were preserved, 

 while awaiting further treatment, in 4 p.c. formalin. The sections are 

 stained with an iodine solution made by dissolving the iodine in 2 p.c. 

 formalin and then adding 25 p.c. sulphuric acid. While the sections 

 are staining, a few drops of 4 p.c. formalin, saturated with iodine, are 

 added : staining is completed in from 2 to 3 hours. The preparation may 

 be mounted in glycerin or balsam, but unfortunately the finer details do 

 not last longer than six months. Another method which gives good 

 results consists in staining sections, which have been fixed in formalin 

 and preserved in alcohol, or subsequently further fixed with aqueous or 

 alcoholic sublimate, with the following solution : anilin oil 3 c.cm., acid- 

 fuchsin 20 grm., H 2 200 c.cm. After treatment with the staining 

 solution for 10 to 20 minutes, they are washed out with a saturated 

 alcoholic solution of picric acid, which has been diluted with 100 c.cm. 

 distilled water to every 50 c.cm. Then follow 96 p.c. alcohol, benzol- 

 alcohol, benzol (in each of which a little picric acid is dissolved), benzol- 

 balsam. 



Staining Celloidin Sections of Nervous Tissue by the Iron- 

 hsematoxylin Method. $ — Marie Loyez fixes the material in 10 p.c. 

 formalin for eight days or longer ; the pieces are carried through in the 



* C.R. Assoc. Anatomistes, 1909, pp. 238-44 (7 figs.), through Zeitschr. wiss* 

 Mikrosk., xxvii. (1910) pp. 294-5. 



t Zeitschr. wiBs. Mikrosk, xxxii. (1910) pp. 243-5. 

 X C.R. Soc. Biol. Paris, lxix. (1910) pp. 311-13. 



