414 PROCEEDINGS OF SECEION C. 
fragments of more or less altered felspars. The felspars are 
orthoclase and plagioclase, and the alteration is to mica. 
The quartz foliations are, as in other cases, bent and drawn 
out. At some little distance up the stream the schists are much 
harder, less micaceous, and more felspathic and quartzose. The 
rock is composed of biotite, quartz, and felspar, with usually 
subordinate muscovite. The felspars, as usual, form “eyes” in 
the foliatures and the larger indurduals are either arranged in 
the line of foliation or more or less across it, just as if slightly 
turned over in the process of rubbing between two planes. The 
portions which have been abraded surround the felspars, and are 
accumulated at the ends, where they tail off into a point where 
the two micacious or quartzose foliatures come together again round 
the felspar crystal. In samples from this place I again observed 
that the erystals of felspar are broken and abraded, and not 
stretched or distorted. The quartz, however, is evidently both 
stretched and bent, indicating a considerable degree of plasticity. 
In order to obtain some further information as to the structure 
of these “eyes,” I examined slices prepared from a felspar’ 
inclusion from this place. It was about an inch in length by 
three-quarters of an inch in the widest part. The felspar proved 
to be orthoclase, in which the extinction was slightly undulating 
in places. At the end it was joined by a mass of fragments of 
felspar and quartz, gradually narrowing off to where the 
enveloping foliations of biotite came together from both sides. 
At one side, where the micaceous foliation touched the felspar, 
crystals of quartz have been formed, some of them having well. 
formed lateral planes. Some of these are at the contact of the 
mica and felspar, others in the felspar itself, with a few plates of 
biotite placed perpendicularly to the foliation. Here and there 
in the orthoclase are quartz crystals, from which cracks radiate, 
and round which the extinction is disturbed, It is evident that 
these quartz crystals and biotite flakes are of secondary origin, 
that is to say, whatever has been the origin of the foliated struc- 
ture of the rock, they are not older than it. There is, therefore, 
evidence here of the formation of biotite mica and the crystalli- 
sation of quartz in the pre-existing crystal of felspar, and also 
that the quartz has been more plastic than the silicates of 
alumina and alkali forming the felspar. 
Schists of this character extend for about a mile in a south- 
westerly direction, where the rocks become more massive, and of 
a character which may be best described as that of a quartz-diorite 
approaching gneiss. When looked at in the block there is 
apparent a certain parallelism of the mineral, which is not always 
to be seen in small samples. 
T found, on examining a rather fine-grained example of such a 
rock, that it was composed of biotite, in rather ragged-edged and 
wasted crystals, numerous triclinic felspars having the appearance 
of oligoclase and quartz. 
