178 Animal Micrology 



cubic-centimeter of the solution. This is a beautiful stain (1 to 3 

 hours) for embryos which are to be mounted entire. 



49. Hematoxylin, Delafield's. See chap, i, reagent 13. 



50. Hematoxylin, Ehrlich's. 



Hematoxylin 2 grams 



Absolute alcohol 100 c.c 



Glacial acetic acid 10 c.c. 



Glycerin 100 c.c. 



Distilled water 100 c.c. 



Ammonia alum 



Mix the glycerin and the water and thoroughly saturate the 

 resulting fluid with the alum. The solution must be exposed to 

 light and air at least 3 weeks to ripen. It is not ready for use 

 until it acquires a deep red color. This solution is an excellent 

 nuclear stain and will keep for years. 



51. Hematoxylin, Heidenhain's Iron. See chap, i, reagent 18, 

 and chap, vi, iv. This stain is used chiefly in the study of cell 

 structures such as centrosomes, chromosomes, etc. Tissues are 

 best fixed in some of the sublimate solutions or in acetic alcohol, 

 although it will follow liquid of Flemming or Hermann. Sec- 

 tions should be not over 6 microns thick. The ferric solution 

 must be renewed occasionally as it soon spoils. 



52. Hematoxylin, Weigert's. This method together with its 

 modifications is a very important one for the study of the tracts 

 of medullated nerve fibers. 



Solution I. 



Neutral acetate of copper, saturated aqueous 



solution 1 part 



Distilled water 1 part 



Solution II. 



Hematoxylin . 1 gram 



Absolute alcohol 10 c.c. 



Lithium carbonate, cold saturated aqueous 



solution 1 c.c. 



Distilled water 90 c.c. 



Solution III. 



Ferricyanide of potassium 2.5 grams 



Borax 2.0 grams 



Distilled water . . 200.0 c.c. 



