MASS DYNAMIC ACTION. 305 
During movement, in some cases, the tendency for large individuals 
to grow at the expense of smaller ones may control, and properly oriented 
individuals grow to a porphyritic size. This is beautifully illustrated 
by some of the albite gneiss of Hoosac mountain and by parts of the 
augen gneiss of the French Broad river. The porphyritic feldspars show 
a marked tendency toward crystallographic orientation, the cleavages 
of the feldspars corresponding with the cleavages of the rocks. 
This argument applies equaily to the cases of the parallel crystallo- 
graphic orientation of individuals which occasionally occur in rocks erys- 
tallizing directly from magmas. Feldspar is not infrequently oriented in 
such rocks, and the phenomenon is known in reference to other minerals, 
Conclusion.—From the foregoing it 1s concluded that the development 
of the crystalline schists is to be explained as a process of chemical re- 
action induced by mechanical action, resulting in the constant solution 
and deposition of the material so as to accommodate it to the changing 
form of the mass. 
Relations of granulation and recrystallization.—Whether granulation or 
recrystallization is the dominant process in a given place in the zone of 
flowage depends upon many factors. Some of these factors are the char- 
acter of the material, water content, temperature, pressure, and rapidity 
of deformation. 
Character of material— Whether granulation or recrystallization occurs 
depends to a considerable extent upon the character of the material. The 
difference appears as a consequence of the presence of different materials 
in varying proportions in different rocks. 
Ina rock the same mineral may be partly granulated and partly recrys- 
tallized. Even the individual grains of a mineral may exhibit the two 
processes in various proportions. In the latter case the fracturing may 
be along the borders of the individuals, may extend entirely across them, 
or granulate them throughout. The simultaneous solutions and deposi- 
tions may be along the borders of the original or the secondary granules ; 
they may be in the spaces produced by the fracturing ; they may regen- 
erate the old mineral particles throughout. Any of the deposited mate- 
rial may be as independent individuals or as enlargements of original 
erains or mechanical granules. In some cases the separated granules 
and cement have a common or nearly common orientation. In the 
different particles of the same mineral in a given rock granulation or 
recrystallization may be the dominant process, 
In the same rock mass certain minerals may be recrystallized and 
others granulated or retain theirintegrity. For instance, it is well known 
that quartz suffers granulation and recrystallization much more readily 
than feldspar. Recrystallization is illustrated by the flat individuals of 
