62 BULLETIN OF THE NATURAL HISTORY SOCIETY, 



this extent would prevent the escape of the river waters 

 at that point and turn the whole into the present outlet. 



In the preceding remarks I have not mentioned 

 another cause which, no doubt, operated to deepen the 

 present outlet at the expense of the one at Drury's cove 

 when once the preponderence of the discharge at the 

 former was established, namel}', the erosion of the rocks 

 at the " Upper Fall." I know of no evidence of this 

 erosion which, nevertheless, is in progress at the present 

 day ; but it will be difhcult to distinguish it from the eifects 

 of the slow subsidence of the land which has been going 

 on in modern times, without special observations having, 

 this end in view. 



Conclusions. 



To sum up the whole matter we may say that — 



1st. The St. John River is built up of three river systems, once inde- 

 pendent of each other. 



Snd. That the river has availed itself of several very ancient valleys 

 for its present outlet. 



3rd. That the pre Glacial discharge was probably by a buried valley 

 on the line of South Bay and Pisarinco Cove. 



4th. That there were four post-Glacial outlets. 



5th. That the post-Glacial outlet by way of Drury's Cove and the 

 Marsh, to Courtenay Bay, persisted longer than two others 

 of the four, but now only one of the four remains open. 



