ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 591 



by fixing a 5 mgrm. tube of radium bromide on the microtome knife 

 ■close to where the paraffin ribbon is forming. Apparently the radiations 

 from the radium discharge the electrification of the paraffin sections 

 by ionising the air in their neighbourhood. 



Fixation and Staining of Eumesostomina.* — A. Luther fixed the 

 objects chiefly with sublimate either in the form of Lang's fluid of 

 medium strength, or as a saturated solution in physiological salt solution. 

 The fixative was used hot, and the objects afterwards washed in distilled 

 water. They were then transferred to graded alcohols (50, 70, 96 p.c). 

 The sublimate was removed by means of iodine immediately before 

 saturation with paraffin. Sometimes Flemming's mixture was used as 

 fixative, the results being good, especially for the eggs of Mesostoma 

 lingua. The stains mostly used were Ehrlich's hematoxylin and eosin, 

 or Benda's iron hematoxylin and eosin. Toluidin blue (1 p.c. aqueous 

 solution for 8 hours) combined with a weak solution of erythrosin (a 

 few seconds) was often successful. Golgi's impregnation method and 

 intra-vitam staining with methylen-blue were failures. As maceration 

 fluid, especially for the isolation of muscle, nitric acid was found 

 serviceable ; 10 p.c. for fresh material, 20 p.c. for that hardened in 

 alcohol. 



Behh. M. — TJber Schnellhartung und Schnelleinbettung. 

 [On rapid hardening and imbedding.] 



Miinchener Med. Wochenschr., 1. (1903) pp. 2256-7, 



Guttmann, C. — Uber Schnellhartung und Schnelleinbettung. 



Deutsche Med. Wochenschr., xxix. (1903) pp. 740-1. 



(4) {Staining and Injecting'. 



Hematoxylin Staining of Nerve-fibres of the Central Nervous 

 System.j — "W. Pavlow recommends that the brain should be cut up 

 into pieces of about 4 cm. diameter, and fixed in Miiller's fluid or 3 p.c. 

 potassium bichromate at 35° C. The fixative should be changed daily 

 for the first week and twice a week afterwards. The pieces are fixed 

 at 35° O. for 3 weeks, and for the next week at ordinary temperature. 

 On removal they are washed in running water for 2 hours, and then 

 transferred to 75 p.c. methyl-alcohol for 3 days ; after this to absolute 

 alcohol for 3 days, and subsequently to a mixture of absolute alcohol 

 and ether for 5 days. They are next placed for a week in celloidin, 

 kolloxylin or photoxylin solutions. The celloidin solution is made by 

 dissolving 10 grin, of celloidin in a mixture of 500 grm. methyl-alcohol 

 and 500 grm. of sulphuric ether. For the kolloxylin or photoxylin 

 30 grm. are dissolved in 800 c.cm. of the ether mixture. 



The pieces of brain are then fixed on wood or paraffin blocks by 

 means of the same mixture, and after the lapse of 15 minutes are placed 

 in 60 p.c. methyl-alcohol. 



The celloidin sections are stained with hematoxylin solution made 

 by dissolving 10 parts of hematoxylin in 100 parts of absolute ethylic- 



* Zeitschr. wias. Zool., lxxvi. 1(1904) p. 3. 

 t Zeitschr. -wise. Mikr., xxi. (1904) pp. 14-8. 



