Proceedings of Scientifie Societies. 1041 
3. The sections are placed in water for a few minutes (not over 
five or ten), and then in a saturated aqueous solution of methyl-blue 
until stained deep blue. 
are then washed, and placed in a saturated aqueous 
solution of acid fuchsin for about five minutes. 
e sections are next to be quickly washed, and placed for a 
Jew seconds in an alcoholic solution of caustic potash (1 per cent.), 
from which they are to be transferred at once to abundant water. 
The color differentiation at once appears: The white matter 
becomes blue or violet, and the gray matter red. Bundles of fibres 
in longitudinal section appear to be made up partly of blue and 
partly of red fibres. Cross-sections show that the difference in 
color among the fibres is due to the presence in varying amount of 
two unlike substances in the medullary sheaths. These substances 
may be distinguished as erythrophilous (red) and cyanophilous 
(blue). The axis-cylinder is uniformly red, while the medullary 
sheaths are variegated. In some fibres the whole sheath is made up 
of cyanophilous matter, in others of erythrophilous matter. In the 
majority of the fibres, the sheath is composed of concentric layers, 
blue alternating with red. 
In the gray matter of the spinal chord may be seen Gerlach’s 
net-work of fine fibrils. Close examination shows that the fibril is 
differentiated into red axis-cylinder and blue medullary sheath. 
Preparations after the above method are not permanent, but they 
sometimes keep for a year or more. 
Such preparations show that the medullary sheath is a structure 
of more importance than has generally been supposed by physiolo- 
gists and pathologists. The hist brought out by this process 
of double-staining appear to indicate a difference in function among 
the nerve-fibres. The division into motor and sensory fibres, as 
Sahli suggests, may not go to the root of the matter. The central 
hervous system may be built up on a much more complicated 
principle of division. 
PROCEEDINGS OF SCIENTIFIC SOCIETIES. 
Kent Screntiric InstirutE oF GRAND Raprps, Micu.— 
The following officers were elected to serve for the year 1888 : 
President, E. S. Holmes; Vice-President, W. A. Greeson ; Recorder, 
C. A. Whittemore ; Corresponding Secretary, E. S. Holmes ; Treas- 
ining may be successful with celloidin sections, p 
they are very thin. It is better, however, to remove the cello 
