266 W. R. BROWNE AND W. A. GREIG. 
inclusions being apatite and a tiny colourless mineral,. 
possibly zircon, surrounded by a pleochroic halo. Altera- 
tion of biotite to chlorite issometimes seen. Tiny needles 
of apatite, not very abundant, are embedded chiefly in 
biotite, orthoclase and quartz. 
Olivine occurs only as inclusions in the pyroxenes, chiefly 
but not exclusively in the clino-hypersthene. For themost 
part it gives little rounded or elliptical sections, often not. 
more than ‘2 mm. in diameter. These have been much 
altered to a green or brown, slightly pleochroic substance, 
with magnetite dust, but enough fresh examples are avail- 
able to make the identity of the mineral certain. Rarely 
a larger grain is to be seen, scored with cracks filled with 
magnetite dust. Sometimes a pyroxene crystal will con- 
tain only a few olivine granules, at other times the inclusions. 
are quite numerous, and while for the most part they are 
optically independent, in some cases adjacent granules. 
extinguish simultaneously. A tendency to peripheral dis- 
tribution of the olivine is noticeable in some pyroxene 
grains. 
As regards the order of consolidation, it is evident that 
olivine crystallized first. A little felspar is sometimes found 
embedded in the pyroxene, so that it possibly started to. 
crystallize in part before the latter. The two pyroxenes. 
sometimes occur in graphic parallel intergrowth, but 
whereas in the parallel growths of the two minerals augite 
is completely enwrapped by clino-hypersthene the converse 
relationship has not been found. It would seem then that 
augite started first, clino-hypersthene subsequently com- 
_mnencing, and the two thereafter crystallizing simultane- 
ously. 
The bulk of the plagioclase separated after the pyroxene, 
although the indenting of some pyroxene edges by plagio- 
clase indicates a little overlap. Hornblende was the next. 
