ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 239 



used was Bouin's picro-formalin, but for small ovaries Eabl's picro- 

 sublimate was preferable. Flemming's and BorreFs fluids were also 

 employed, but only for small ovules. The material was then passed 

 through upgraded alcohols (80°-80°), 24 hours each. For imbedding, 

 chloroform was used as the solvent for paraffin (m.p. :'>^'^). Heidenhain's 

 bisulphide of carbon method was also employed for imbedding.* The 

 advantage of this procedure consists in the shortening of the heating 

 time. The paraffin sections were stuck on by the albumen method, the 

 paraffin removed by toluene and the picric acid and toluene by alcohol. 

 As a nuclear stain hasmalum served the purpose best. The cytoplasm 

 stains used were (1) aqueous solution of eosin ; (2) acid-fuchsin : (:^) 

 Squire's acid-fuchsin and orange ; (4) modification of Pappenheim's stain 

 (eosin 6, orange 4, aurantia 1, distilled water 500). Some of the fore- 

 going lose their colour during dehydration, but this inconvenience may 

 be avoided by a previous washing in water slightly acidulated with acetic 

 or hydrochloric acid. 



Another nuclear stain was the following: indigo-carmin 0*25, 

 saturated solution of picric acid 100. For the osmic acid preparations 

 the author used safranin and magenta-red as nuclear stain, picro-indigo- 

 carmin and light green for the cytoplasm. 



Studying the Structure of Spinal Ganglia.f — M. v. Lenhossek 

 made the cliief object of his research the spinal ganglia of adult 

 men, but also examined the ganglia of infants, cats, dogs, horses, 

 and cattle. Small ganglia were immersed entire, large ones were 

 cut in half and immersed for 24 hours in the following mixture : alcohol 

 96 p.c. 100, ammonia 0'5. The pieces, after a rapid wash in distilled 

 water, were placed in 2 p.c. silver-nitrate solution, and incubated for 

 3 days at 35°. The pieces, on removal, were washed in distilled water 

 and exposed at room [temperature to daylight for 24 hours in the follow- 

 ing mixture : pyrogallic acid 1*5, distilled water 100, formalin 5. After 

 dehydration the pieces were imbedded in paraffin and sectioned. The 

 sections are then (after the paraffin has been removed in the usual way) 

 treated with gold solution prepared as follows : — to 150 c.cm. of distilled 

 water, 4 c.cm. of the ordinary 1 p.c. gold chloride solution are added. 

 After an immersion of 10 minutes to an hour in order to exchange the 

 silver for gold, a point recognisable by the naked eye by the alteration 

 from a brown hue to a steely-grey hue, the preparations are treated for 

 some minutes with a 5 p.c. solution of soda-fixative. This done, they 

 are thoroughly washed in running water. The transfer of gold for silver 

 may be more safely ascertained by watching the process under the 

 Microscope. The sections may, in addition, be contrast-stained with 

 Mayer's carmalum. 



Fixation of Red Blood Corpuscles.| — F, Weidenreich fixes the red 

 corpuscles in the following way. Some 1 p.c. osmic acid is placed in 

 shallow glass vessels, and the slides to be used are exposed to the vapour 

 for 1 minute. The blood obtained from a clean finger tip is then run 



* See this Journal, 1902, p. 111. 



t Arch. Mikr. Anat. u. Entwickl., Ixix. (1906) pp. 245-63 (2 pis.). 



X Tom. cit., pp. 389-438 (2 pis.). 



