210 BOTANICAL MICROTECHNIQUE 



examination at various stages in the process of staining, to correct errors. 

 The commonest mistake is to overstain with gentian violet. 



Should orange G be brought into the combination, 'the slide after re- 

 moval from gentian violet is rinsed in vs^ater and placed in a 1% aqueous 

 solution or a dilution of this strength. It is left from ten to thirty sec- 

 onds in this stain and then treated w^ith absolute alcohol and cleared in 

 oil of cloves as described above for the gentian violet. The orange G, 

 if successfully used, will give a grayish tinge to the cytoplasm, while 

 the spindle fibers (kinoplasm) will be blue and the nucleolus and chro- 

 matin red. The combination, when successful, is the most striking 

 stain known for nuclear figures. 



Slides should not be destroyed if the results are not up to expecta- 

 tions. If the protoplasm is uniformly blue, structures may still show 

 fairly well, and if the stain is too weak, the balsam may be removed 

 with xylol and the slide stained again. It is not necessary to use 

 orange G, and in our own practice this stain is generally omitted. 



E. Safranin and BelafieWs hoematoxylin. This combination, applied as 

 outlined in Sec. 185, is excellent for the staining of tissues, without 

 much regard for the details of protoplasmic structure, such as nuclear 

 figures, etc. 



F. Other stains. Other anilin dyes besides safranin and gentian violet are 

 frequently used in staining on the slide. Fuchsin (Sec. 186, A), methyl 

 green followed by fuchsin (Sec. 186, B), and erythrosin after hsematoxy- 

 lin, or blue or green anihn stains (Sec. 186, C) give good results for the 

 study of tissues. They are especially satisfactory for the differentiation 

 of structure in fibro-vascular bundles. 



