1901] MICROSCOPICAL JOURNAL. 161 
in this respect. It must be remembered that the horse- 
shoe foot is more easily gripped and held firmly in its case 
than the tripod, but a strong and neat fitting for the lat- 
ter ought not to be beyond the powers of the ingenious 
to contrive. 
It may be fearlessly stated that a good day is coming 
yet for British microscopes if the makers do but set their 
houses in order, and in addition to providing the most 
sound and accurate instrument that can be, they give due 
consideration to every detail which will make them accept- 
able to those who are influenced by appearance. There 
is no disgrace in making a microscope and its case orna- 
mental as well as useful.— Knowledge. 
Microscopical Notes. 
M. J. CROSS. 
For Knowledge. 
STAINING Livine BactLuI1.— We have had placed in our 
hands an interesting paper by Mons. A. Certes dealing 
with the selective coloring power of the spore-bearing fil- 
aments of the living Spirobacillus gigas with methylene 
blue, and the following is a brief reswme of it. 
He remarks that the experiments of Brandt, Henneguy 
and himself, dating from 1881, prove that living proto- 
plasm can absorb certain aniline colors, but little has been 
done by biologists in the study of the action of coloring 
substances on living microbes. It has been found that cer- 
tain microbes cease to live on being stained, others absorb 
the stain and still remain alive, while others do not ab- 
sorb the stain either alive or dead. 
The difficulty of making observations on selective col- 
oration is obvious on such delicate subjects as bacteria, 
but M. Certes was fortunate in discovering the Spiroba- 
cillus gigas in the reservoirs at Aden ; the length of these 
is usually 150-160 mikrons, but they are occasionally 
found 400 mikrons long. 
