848 The American Naturalist. [October, 
Cellular Epidote in Granite.—Three granite sections from 
Wrangell Island, Alaska, the Pelly River in the Yukon District, and 
from the Stikine River, in the Coast Range of British Columbia, are 
described by Adams’ as exhibiting several interesting peculiarities. 
All possess large quantities of epidote, which has a rudely outlined 
crystal form. In the specimen from the first mentioned locality the 
epidote is intergrown with allanite, with the latter on the interior. 
The most peculiar feature in connection with the epidote is its cellular 
structure, it being merely a skeleton of this substance enclosing small, 
elbow-shaped areas of quartz, feldspar, etc. Calcite and muscovite 
grains were noted with the same structure. In the case of the mica 
the inclusions occupy such a large portion of the area enclosed within 
the outline of the mineral that the muscovite appears as an assemblage 
of detached fragments, optically continuous with one another. Upon 
discussing the origin of the cellular minerals the author is compelled 
to the conclusion that they have all been formed since the consolida- 
tion of the rocks in which they occur. Since these all show evidence — 
of having undergone slight crushing, it may be that the growth of the 
minerals is dependent somehow upon the reactions set up during the 
crushing. As all the constituents in these granites are fresh, the con- 
clusion that the calcite, muscovite and epidote are secondary is an 
interesting one. 
Petrographical Notes.—In an article descriptive of Chilean ore 
deposits Moricke* gives a few petrographical notes on a hornblende- 
biotite granite, a tourmaline granite, a quartz diorite, a quartz por- 
phyry, and two other rocks of special interest. One is a quartz tour- 
maline rock in which a sort of groundmass of the former mineral 
encloses small idiomorphic crystals of the tourmaline. It is presum- 
ably an eruptive. The other is a perlitic pitchstone from Guanaco, 
with large phenocrysts of plagioclase and sanidine and a few flakes of 
biotite. Its unique feature is the possession of gold in skeleton crys- 
tals scattered through the glassy matrix, enclosed in the spherulites 
and included in the fresh feldspar———Masses of an azure blue sac- 
charoidal’ rock occur imbedded in a granular serpentine at a point on 
the Gila River, 40 miles west of Silver City, N. M. In the thin sec- 
tion these masses are found to be composed of a granular, colorless — 
"Canadian Rec. of Sci., Sept., 1891, p- 344. 
*Min. u. Petrog., Mitth. xii, p. 195. 
°Merrill and Packard, Amer. Jour. Sci., April, 1892, p. 279. 
