574 CHIL. 
ral bands. (d) The complication of veins and islets of micaceous 
gneiss in figure 6; the long line of the same micaceous gneiss in the 
material of the veins which graduate into the feldspathic granite 
either side; the irregular sizes of the intersecting veins, and especially 
the fact that the one below on the right is very narrow compared with 
its continuation above to the left ;—all these points are unlike any de- 
scribed veins in volcanic regions. (c) The singular mode of intersec- 
tion in figure 7, and the character of the included micaceous gneiss, 
its width much exceeding that of the granite strands either side, are 
peculiarities differing from known injected dikes. (d) The intersec- 
tion in figure 8 presents the same difficulties, which are farther 
heightened by the singular subdivisions of the intersecting veins. 
(e) Again, there are seeming objections to the theory of injection in 
the singular faultings represented in figure 14, for there is no way 
of joining the separated parts so as to make them continuous; so 
also in figure 17, the parts are of unequal size, and do not fit one ano- 
ther ; in figures 10 and 11, which are but six feet 
Hie oale apart and parallel, the faults are different in 
ass number and direction; and the same is true of 
A and B, figure 15. (/) Besides, the micaceous 
structure about the vein, in figures 6, 7, 8, must 
have been induced by the heat, if they are veins 
of injection, which is contrary to the deductions 
of many geologists, who attribute the structure to a previous lamina- 
tion arising from a sedimentary origin. 
Several of the above-mentioned difficulties in the way of the theory 
of injection are only apparent. If in the faulting of a rock, there is a 
lateral as well as an up and down slide, that is, if the displacement 
from fractures is oblique, the several parts of a faulted vein, as pre- 
sented on a surface section, should not necessarily have the same 
breadth; and besides, the faultings of adjacent veins, as seen on an 
exposed surface, might differ in number and direction. Even the 
peculiarities in figure 14 may be fully explained on this ground. The 
interruptions in figure 16 are understood if we consider that they may 
all connect with a single vein beneath the surface, just as wood which 
is widely cleft on one side may have the cleft show itself on the oppo- 
site side, in a few rents following parallel lines. The objections e are 
therefore of no weight. 
The last objection (f) is merely imaginary, since it is now esta- 
blished that the schistose structure may be a result of the crystalliza- 
