150 BOTANICAL GAZETTE. [June, 
for the herbarium and ready examination under the microscope, which Dr 
now uses, and which the writer had the pleasure of seeing upon a recent 
visit, Instead of using small boxes, which are somewhat awkward for plac- 
ing under the microscope, the specimens are 
~ mounted in a metal cell, which is firmly 
ELL CAP fastened to an ordinary glass slide, and pro- 
THE PIERCE CELL. vided with a close-fitting metal cap. The 
bottom of the cell is covered with dark green wax, on which the material is 
mounted so as to give both vertical and lateral views. The cap is so nicely 
made as to exclude dust and insects and yet be readily removed for examina- 
in the herbarium, as explained elsewhere in this number. This cell was de- 
vised by Mr. J. Pierce, of Providence, R.I. We are indebted to J. W. Queen 
& Co. for the use of the cut illustrating it. 
BACTERIA (ScHIZOMYCETES). —Bacteria are commonly preserved for the 
herbarium by drying some of the zooglea, or drops of fluid swarming with 
them, on bits of mica, and placing these in small envelopes gummed or pinned 
to the herbarium sheet. They are apt, however, to flake away from the mica 
after a time and may ultimately be entirely lost, as the dried film 1s exceed- 
ingly friable. To obviate this difficulty the specimen may be incorporated 
with a drop of some mucilaginous substance, like Althea extract, freshly pre- 
pared and filtered. It has been asserted that this preserves their vitality, so 
that they may be used for starting new cultures after a long duration in the 
No specimens are so satisfactory for study as mounted slides, prepared by 
smearing a very thin film of distilled water containing the bacteria over the 
middle of a slide, drying it rapidly (but without heating too much) over an 
alcohol lamp, staining with a drop of freshly-filtered fuchsine, methyl violet, 
r some other aniline dye, which is removed at one side by a bit of blotting 
paper, after which the slide is dried as before, a small drop of fluid balsam or 
benzole-balsam added, and a cover-glass at once applied. 
Few persons are aware how easy it is to obtain a sagan number of 
pigment sii several of which I have described i “ Observations on 
” all that is necessary being to rub pieces ee) oiled potato about 
on the joa s in sinks, etc., where dust collects, and set them away for a few 
days, covered by inverted samtlens to keep them moist. 
slide or herbarium specimen is worth much unless accempanied by 
full notes on the nature and color of the zoogloa it comes from, or the effects it 
uces; and a slide or specimen which contains more than one species is an 
abomination which had best be destroyed as soon as made, before it has oppor- 
tunity to do harm.—WILiiAM TRELEASE. 
YEAST \Soapircearisg eine ae, pet should be spread out in a thin 
layer on pieces of mica or glass. The pieces can be moistened in spots 4 and 
used as microscopic slides e answer well a for the comparisons of dif- 
ferent forms.—W. G. FarLow. 
