144 The Botanical Gazette. {March, 
In such cases small pieces of camphor-gum strewn in the water 
help to keep the alge from putrefying until they can be 
studied or properly sorted and preserved. Formalin is use- 
ful also for this purpose, but the acidity produced changes the 
color quicker than is the case in camphorated water. For — 
preserving Cyanophycee, camphor water keeps the cell 
structure well if present in large volume, proportional to the 
amount of material, but the coloring matter is soon dissolved. 
Chlorophycee, Phaeophycex, and Rhodophycee, if wel 
sorted and cleaned, are well preserved in abundance of tht 
fluid, even the finer details of cell structure being preserved 
perfectly. But perhaps the most important use of camphor 
water is to preserve specimens already fixed by other fluids 
Specimens of the larger Rhodophycee, killed and fixed in 
concentrated aqueous solution of picric acid are preserved to 
especial advantage in camphor water; as one of us has expt 
rienced in special work upon Rhabdonia tenera Ag. 
Summary of results. 
Cyanophycee are best prepared with a solution containing 
I per cent. chrome alum and I per cent. formalin. This % 
lution renders the gelatinous sheath and matrices firm, keeps 
the cell contents in a very natural condition, and retains 10 
most cases the colors in their ordinary tints. 1-2 pet cent 
formalin solution preserves the cell contents very well indeed, 
but does not keep the color well, or the softer gelatinous 
sheaths and matrices. Camphor water is not very favo 
for many blue-greens. Many species must needs be preserved 
in mass, and are associated with many bacteria and the ca 
phor solution is hardly strong enough to wrestle successtilly 
branaceous forms like Ulva Lactena. Such forms ate 
course better if placed in simple formalin solution. ft 
Phaeophycee do well when placed immediately in ! P 
cent. formalin in seawater. The larger forms are better e 4 
in I per cent. chrome alum for a few hours (3-6) and wT 
preserved in 2 per cent. formalin solution or camphor vs 
But specimens for crushing may be allowed to remain indefir 
itely in the chrome alum solution. | 
