510 TRANSACTIONS OF THE CANADIAN INSTITUTE. [Vov. VIII. 
alluded to in the preceding paragraph, occur invariably in the presence 
of calcite, and apatite crystals found imbedded in other rocksshow this 
peculiarity in a lower degree. 
46. Other minerals occurring along with apatite in connection with 
calcite exhibit to a certain extent the same peculiarities. A specimen 
of black hornblende from Otty L. which I collected, had scattered inclusions 
of rounded apatite grains. In another specimen similar rounded grains 
of calcite were found in a crystal of augite. Finally a number of speci- 
mens in the University laboratory consisted of calcite in which were scat- 
tered small crystals of hornblende and augite which showed the same 
rounded edges already noted in the case of apatite. 
47. Two other specimens showed characteristics which have a bearing 
upon this discussion. A specimen in the University museum consists 
of a hornblende pierced by interpenetrating apatite crystals. The large 
phlogopite crystal observed by the writer in the Lacy mine gives an 
indication of the very slow cooling of the magma. 
48. These facts throw considerable light upon the order of events 
in the formation of the apatite deposits. Crystallized out of a magma 
cooling so slowly that a crystal of phlogopite of several tons weight could 
be produced as well as the enormous crystals of apatite of several hundred- 
weight as in the specimen in the museum, the apatite crystallizing first 
could form inclusions of a size to be measured in inches. Subsequently 
an increase of heat, while the deposits were still under great pressure 
reduced the apa‘ite when in contact with calcite, to a liquefiable mass. 
It is evident that this was not the result of heat alone as it only occurs in 
the presence of calcite. 
VI.—EvVIDENCE FROM ASSOCIATED MINERALS. 
49. A characteristic of the occurrence of the Canadian apatites is 
the constant presence of certain associated minerals. Phlogopite, calcite, 
graphite, magnetite, anhydrite, and several others are found in varying 
quantities in every apatite deposit. This fact throws considerable light 
upon the origin of the apatite, more especially in the case of the four 
last mentioned, whose bearing on the problem will be discussed seriatim. 
50. Calcite is the commonest ‘‘vein-stone”’ in all apatite deposits, 
and its presence is one of the distinctive peculiarities of the Canadian 
deposits. It is worth remembering that analogy would suggest an organic 
origin for all calcite. To be sure*it is conceivable that the primordial ocean 
