STAINS AND STAINING 71 



Directions for staining in safranin and Delafield's haematoxylin are 

 given in the chapter on "Freehand Sections" (chap. vi). 



Heidenhain's iron-haematoxylin and orange G. — This haematoxy- 

 hn is very satisfactory when used alone. A hght staining in orange G, 

 however, sometimes improves the mount. After the last washing in 

 water, stain for about 30 seconds in orange G ; or, if the orange is in 

 clove oil, stain after dehydrating in absolute alcohol. 



Eosin, erythrosin, and most plasma stains fail to increase the effect 

 of a good stain in iron-haematoxylin ; but staining overnight in safranin 

 and reducing the stain until it becomes a faint pink in the protoplasm 

 may still show a distinct red in the nucleoli. Then stain in iron-alum 

 haematoxylin in the usual way. 



Combinations might be described almost without limit. Several 

 more will be suggested in Part II in connection with various groups of 

 plants. 



We have not tried to make the Ust of stains complete, but we have 

 described more than any botanist will learn to use critically. Master 

 two or three good combinations and don't spend much time with the 

 rest. 



