1884. 53 Trans. N. Y. Ac. Sci. 
January 21, 1884. 
SECTION OF BIOLOGY. 
The President, Dr. J. S. NEWBERRY, in the Chair, 
Sixty persons were present. 
Mr. G. F. Kunz exhibited two specimens of corundum from 
North Carolina—the one a crystal of 13 grammes—the other, weigh- 
ing 3.15 karats, cut ex cabochon, probably the most perfect star 
sapphire ever found in the United States. Both were of a rich light 
brown color, very compact, and resembled a variety of sapphire 
from the ‘ Hill of Precious Stones’’ in Siam. 
A paper was then read by Prof. H. L. Fatrcui1p, illustrated 
with the lantern, on 
METHODS OF ANIMAL SELF-DEFENCE. 
DISCUSSION. 
The PRESIDENT remarked on the character of the dentition in the 
sabre-toothed cat, Machairodus, of which the canines of the upper jaw 
project seven or eight inches, and were curved, compressed, and 
sharp-edged. In the Tertiary age such teeth were common to many 
carnivorous animals not closely related, and seem to have been instru- 
ments fitted and employed for reaching the vital parts of other ani- 
mals especially protected by bony armor. In ancient times, a constant 
competition had been going on between the means of offence and 
defence. This was well illustrated by the strife now maintained be- 
tween the weapons and armor of men and ships in human warfare. 
Some of the ancient animals were better provided with means for 
attack and defence than any in later times—for example, the mail- 
clad ganoids and spine-bearing sharks of the Devonian and Carboni- 
ferous seas, the formidable teeth and claws of Megalosaurus and 
Lelaps, and the thick bony plates and enormous spines for defence of 
Stegosaurus ; also the great canines of Machairodus, and the impene- 
trable carapace of the contemporaneous Glyftodon. In the latter 
case the huge armadillo was probably vulnerable only at the throat, 
and the sabre-like teeth of Machairodus were probably used to pene- 
trate that part. 
Geology furnishes many examples of the nice adaptation of means 
of defence among the herbivorous animals against the weapons of 
the carnivora, but it is a remarkable fact that we find very few 
