514 TRANSACTIONS OF THE CANADIAN INSTITUTE. [Vo.. VIII. 
lations of phosphatic organic material, which may have increased their 
percentage of phosphoric acid by condensation from sea water. 
(2) The phosphates thus formed absorbed fluorine from the water 
in which they lay tending to form the stable apatite molecule. The 
fluorine was in certain cases molecularly replaced by chlorine, thus causing 
the various kinds of apatite. Subsequent metamorphosis finally gave 
the calcium fluo-phosphate the crystalline form of apatite. 
(3) The peculiar corroded appearance of the apatite is due to the 
action of the associated calcite while in more or less fluid condition. 
60. In conclusion, I wish to express my thanks to Professor A. P. 
Coleman, at whose suggestion this research was undertaken, and who has 
supplied me with much of the material used. 
