ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 025 



phate or of sugar, it is no longer possible to impregnate the tissue ; 

 and, per contra, if such a dechlorided membrane be treated with 

 physiological salt solution, the tissue is then as effectively impregnated 

 as is fresh membrane. These facts explain why nervous and other 

 tissues often fail to become impregnated — they have been accidentally 

 dechlorided. 



Physiological Injection for Studying Development of Enamel.* 

 H. Ganzer studied the histogenesis of enamel by means of injections of 

 saturated solutions of sulphindigotate of soda. Results of several 

 experiments are given in tabular form, the most satisfactory being : 

 subcutaneous injection of 4 c.cm. for two successive days followed 

 after an interval of a day by injection of a similar quantity into the 

 peritoneal sac. The animal was killed after the lapse of three-quarters 

 of an hour, and it was found that the non-calcified parts of the teeth 

 were stained deep blue. The other result was obtained by injecting 

 4 c.cm. into the peritoneal sac, and killing the animal three-quarters of 

 an hour after. In this case the non-calcified parts were of a sky- 

 blue hue. 



Demonstrating Nerves in Female Genital Tract.f — F. Worthmann 

 studied the nerves and nerve-endings of the clitoris and vagina by the 

 methylen-blue method. Pieces of quite fresh tissue were sectioned 

 between slips of elder-pith. The sections, placed on a slide, were treated 

 with 5V p.c. methylen-blue in physiological salt solution and incubated 

 for about 10 minutes at 85°. If, when placed between two slides, they 

 showed, on inspection under the Microscope, a good staining of the 

 coarser nerves, they were transferred to 7'5 p.c. aqueous solution of 

 molybdenate of ammonia for 6-8 hours. If not properly stained, they 

 were replaced in the methylen-blue solution for 5-10 minutes, and then 

 if nothing were to be seen, they were rejected. 



On removal from the molybdenate solution the sections were washed 

 in frequently changed distilled water for 2-4 hours. Some sections 

 were then very rapidly dehydrated in absolute alcohol, and, after xylol, 

 mounted in balsam. Other sections were, on removal from water, cleared 

 in glycerin, and then mounted in glycerin jelly (Beale's formula). 



Demonstrating the Regeneration of Peripheral Nerves.J — P. 

 Krassin demonstrated the centrifugal course of regeneration of peripheral 

 nerves after division by intra- vascular injection of 1 p.c. methylen-blue 

 in physiological salt solution, or by immersing the preparations for a 

 period in weaker solutions ( t V-tV P- c -) °f the same pigment. The 

 staining was fixed either by means of a saturated aqueous solution of 

 ammonium picrate, or by a 5-10 p.c. aqueous solution of molybdenate 

 of ammonium. 



Simple Method of Staining S pores. § — 0. Orszag mixes up the 

 bacteria in a drop of fluid composed of h p.c. sodium salicylate 4 parts, 



* Anat. Anzeig., xxviii. (1906) pp. 436-42. 



t Arch. Mikrosk. Anat. u. Entwikl., lxviii. (1906) pp.122-36 (2 pis.). 



J Anat. Anzeig., xxviii. (1906) pp. 449-53. 



§ Centralbl. Bakt. Orig., xli. (1906) pp. 397-400. 



