216 F. MARTIN DUNCAN ON 



objects. The rest may be rouglily floated on to slieets of cartridge 

 or botanical paper and stored away. 



For many years past I have employed the following method, 

 originally devised by my old friend Mr. J. T. Neeve, of Deal, for 

 mounting the fruiting organs of seaweeds : On the work-table 

 have ready three deep, half-plate size stoneware developing 

 dishes, or three ordinary soup-plates. Two of these should be 

 filled with filtered sea-water and the third either with filtered 

 sea-water or tap-water. If red seaweeds predominate, then fill 

 your third dish with sea-water, as some are apt to change colour, 

 or discharge their colouring matter, if placed in fresh water. The 

 whole specimen is first placed in No. 1 dish for a preliminary 

 wash, and while there examined with a pocket lens of x 8 or x 10 

 for any branches that may bear reproductive organs. These 

 branches are cut off, placed in dish No. 2 and washed, and 

 then carried on to dish No. 3 for final cleansing. When all have 

 been transferred to No. 3 dish, we may at once proceed to mount 

 them, or they may be stored away in a preservative fluid. It is as 

 well, however, to mount at once, even roughly, if circumstances will 

 permit. A 3 in. x 1 in. slip is warmed, a small quantity of Deane's 

 Medium poured on to it, the frond is arranged in position with 

 the help of warmed needles, and a warmed cover-glass then gently 

 lowered from one side on to the slide. The slides are then set 

 aside out of reach of the dust for a couple of days, when the exuded 

 medium can be carefully cleaned off, two or three rings of good 

 gold-size applied, and, v/^hen these are thoroughly dry, the mount 

 finished off with a couple of rings of asphalt cement. Deane's Medium 

 can be obtained through any vendors of microscopic reagents, and 

 is a very valuable mounting medium for this work, greatly 

 superior to the ordinary glycerine jelly. It will be found that fronds 

 of seaweeds, and also delicate Mosses, keep their colour well and 

 retain their natural beauty when mounted in this way. Fronds 

 of seaweeds may be stored away in glass tubes filled with a solution 

 of sea- water and formalin, made by adding one part of 40 per cent, 

 commercial formaldehyde to nine parts of filtered sea-water. 



If you propose studying the minute cell contents, rather 

 than the external morphology, then you will have to immerse 

 your freshly gathered specimens in one of the fixative solutions 

 used for cytological work. Bouin's solution is a very satisfactory 

 all-round one to employ, and is made up as follows : 



