1885.] Anthropology, 729 
or white and the non-medullated or gray nerve fibers. Contrac- 
tion of involuntary muscle is brought about exclusively by im- 
pulses proceeding along the non-medullated nerves, while relaxa- 
tion or inhibition of muscular contraction is as invariably produced 
by impulses conducted by the medullated nerves. All nerves in 
their course from the spinal cord to the sympathetic ganglia are of 
the medullated variety, but on leaving the sympathetic ganglia 
they are separable into two groups of medullated and non-me dul- 
lated fibers; the medullated sympathetic fibers are, Soe 
easily distinguished from those of ordinary striated muscle by 
their smaller diameter. 
Dr. Gaskell writes: “In previous communications I have 
shown that the heart of various cold blooded animals, e. g., frog, 
' tortoise, crocodile, is innervated by nerves coming from two dis- 
tinct scurces in the same way as the heart of the warm-blooded 
animal; and I am now enabled to make the further communica- 
tion that in the dog, cat, rabbit, tortoise and crocodile these two 
sets of nerve fibers are structurally differentiated from each other 
in precisely the same manner. The vagus fibers from their origin 
up to their entrance into the heart are medullated, the sympa- 
thetic fibers in the whole of their course from the basal ganglia 
of the Aap ale ie along we annulus of Vieussens to the heart are 
non-medullated. very involuntary muscle is inner- 
vated by rotor nerves which are histologically and physiologically 
distinct; the one gray, non-medullated, causing contraction of 
the muscle; the other white, fine, medullated, causing relaxation 
of the muscle.’ '— Jl. of Physiology, Vol. vi, p. tv. 
ANTHROPOLOGY .' 
THE AMERICAN ANTIQUARIAN.—This valued exchange has now 
oe a bi-monthly. The anthropological papers of No. 5, Vol. 
AR mihol. By F. G. Flea eay. 
Dates in the ancient history of S, America. By M. Castaing: 
The hill tribes of India. John Ave nig 
Emblematic mounds. By S. D. Pee 
The paper of Mr. Avery is sof great value, not e in naming 
and describing tribes, but in the explanation of certain customs. 
The article by the editor relates to the attitudes of the animals in 
the emblematic mounds, and supports the view that the construc- 
tors had in mind the various poses of the animals, which are 
familiar to hunters. 
METALLURGY AMONG Savaces.—Dr. Richard Andrés has just 
1 Edited by Professi Otis T. Mason, National Museum, Washington, D.C. 
