Hunt.] 262 [J anuary 15, 
Shaler, in a communication to this Society, on Feb. 3, 1869, at- 
tempted to explain in this way the concentric lamination of granite 
(long since described by Von Buch), referring it to movements of con- 
traction and expansion in the mass caused by the changes of the sea- 
sons. Dr. Hunt had elsewhere defended this view of Shaler’s (Amer. 
Jour. Sci., July, 1870, p. 88), and called attention to the fact that 
the divisional planes are conformable to the present surfaces of the 
granite masses, and moreover that they are not confined to eruptive 
granites, like those of Rockport, Mass., and Biddeford, Me., but are 
equally well seen in the granitic gneisses of the White Mountain se- 
ries; as for example, near Augusta, Me.,and Berlin Falls, N.H., where 
a nearly horizontal lamination intersects the almost vertical, but ob- 
scurely marked, stratification of the rock. To the action of this 
process on a small scale is due the rounded and boulder-like forms 
of detached masses of granite, which are often found resting upon or 
near the parent rock. Of these there is a remarkable display in 
many places near the frontier of Maine and New Brunswick. A 
similar concentric structure is very generally seen in the weathering 
or superficial alteration of angular masses of rock, the lines of chem- 
ical change within which become more and more rounded in reced- 
ing from the surface, in obedience to the same law which we have 
noticed in the conduction of heat, and which applies equally to the 
penetration of meteoric waters, which are in this case the agents 
producing the alteration. 
Dr. Kneeland observed that their peculiar form must have 
been given to the domes of the Yosemite before the glacial 
period, as they are beautifully polished and striated; and 
showed that the Royal Arches, so called, indicate that the 
concentric structure of these granitic mountains extends to 
a great depth beneath the surface. 
Dr. T. M. Brewer exhibited the specimen of Anser fron- 
talis, lately shot in North Carolina, and presented to the So- 
ciety by Gardner Brewer, Esq. This is the fourth specimen 
known, and is interesting in showing some variations in the 
direction of A. gambellii. 
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