872 Transactions of the Society. 



section, the scarlet staining being mostly central, renders the 

 differentiation most effective. In each of these sections the walls 

 of the central cells are green, their contents light scarlet. 



The atlas-scarlet and mixed green dyes, the malachite being in 

 excess, double stain sections of potato with most precise differentia- 

 tion, the starch-grains in rich green, the loculi in scarlet ; the depth 

 of colour depending upon the length of exposure to the staining 

 solutions. Each staining should be carried out separately, washing 

 in water containing a trace of a very dilute sulphuric acid. These 

 sections also, should be mounted in dammar solution. 



With the exception of the picro-carmine, the colours mentioned 

 in this communication were obtained from Messrs. Brooke, Simpson, 

 and Spiller, 50 Old Broad Street, London. 



