172 Modern Microscopy 



stain for at least half an hour ; then just rinse in methylated 

 spirit, clear in clove-oil, and mount in Canada balsam. The 

 advantage of this method is that the section can remain in 

 the green stain for any time. The writer keeps a stock of 

 sections in it ready for mounting. Should a specimen be 

 overstained green, the excess of colour can easily be re- 

 moved by soaking in methylated spirit for a few minutes. 



Staining with Eosin. — Make a 2 per cent, solution of 

 eosin in alcohol, filter if necessary, and keep in a stoppered 

 bottle. This stain is used for showing the structure of 

 sieve - tubes and plates ; it stains protoplasm deeply. 

 Make transverse and longitudinal sections of the stem of 

 a vegetable marrow, and immerse them in the above for 

 ten minutes. Then wash out any excess of colour with 

 methylated spirit, clear in clove-oil, and mount in Canada 

 balsam. 



Staining Hairs on Leaves. — Make a 2 per cent, 

 aqueous solution of soluble aniline blue and filter. Now 

 take, for example, a young leaf of Deutzia scabia, cut it 

 into small pieces of about I inch square, and bleach in 

 chlorinated soda. Then wash well in water, and immerse 

 in the above stain for twelve hours, wash well in water, 

 and transfer to methylated spirit, in which they must be 

 soaked until nearly all the colour is removed. Then soak 

 in clove-oil for several hours, and when quite clear mount 

 in Canada balsam. 



Leaves of eucalyptus and other plants showing essential 

 oil glands may be treated in the same way, but if the 

 specimens have been preserved in spirit they must be 

 soaked in water before the bleaching process. 



Male and Female Conceptacles of Fucus and other 

 Algae. — Place the specimens in methylated spirit, which 

 must be changed every twenty-four hours for the first three 

 days, then let them soak for ten days or until required for 

 cutting into sections. 



Embed a conceptacle in carrot, place in microtome, and 

 make transverse sections which must be as thin as possible. 



