870 Transactions of the Society. 



dark blue in appearance, wash them rapidly in spirit of wine to 

 remove superfluous green, then let them lie in absolute alcohol for 

 a few minutes to remove water, and mount in Klein's dammar 

 solution. 



Stirling recommends that the stained sections should not be 

 left too long in the spirit, which partially removes the dye.* The 

 same precaution, I should remark, must be taken with the mala- 

 chite-green stain, either alone or combined with iodine-green. I 

 have found from five to ten minutes amply sufficient for the 

 purpose. 



Vegetable Tissues. 



Strikingly beautiful^ as sections of some animal structures un- 

 doubtedly are, when successfully stained with picro-carmine, iodine 

 and malachite-green dyes, sections of many vegetable tissues are 

 also susceptible of very fine double staining, and occasionally of 

 fine treble staining with atlas-scarlet, soluble blue, iodine and 

 malachite-green dyes. 



Let sections cut from the recent stems lie in spirit of wine 

 for about a fortnight, but when not required for immediate obser- 

 vation, store them in Price's glycerine for a couple of months, 

 which renders them, when dammar mounting, not so liable either 

 to fold or break as they are when stained immediately after cutting. 



I shall now, for brevity sake, direct a section of palm stem to be 

 taken through one of these staining processes. 



Place the section in a bottle containing a tolerably dark-tinted 

 solution of atlas-scarlet in spirit of wine. Leave it in this solu- 

 tion (corking the bottle tightly) until it has become of a uniform 

 scarlet tint. But like sections of animal tissues undergoing the 

 double staining process in scarlet and blue, which I have already 

 described, t the section may be left in the scarlet solution for many 

 weeks without risk of counteracting the energy of the green dyes. 



I have recently found in my collection, a store bottle containing 

 sections of the spinal cord which had been lying in atlas-scarlet 

 solution for more than twelve months. I submitted a few of the 

 sections to the action of the soluble blue and obtained very perfect 

 double stainings in scarlet and blue, proving that the second stage 

 of the process, the blue staining, may, with but little risk of failure, 

 be almost indefinitely postponed. 



I do not, however, wish to speak positively regarding the 

 conduct of atlas-scarlet with iodine and malachite-green dyes in 

 multiple stainings of vegetable sections, and think it better to re- 

 commend the completion of the process when the sections seem 

 coloured deep scarlet. 



Should the section have the desired scarlet depth of colour, 



* ' Text-Book of Practical Histology,' p. xlv. t -A-ntc, p. 573. 



