REPORT OF THE DIRECTOR I916 205 



Granting that the whole class of these parallel channelings and 

 striations are of the mechanical origin suggested, I must say that 

 my experience and observation do not justify the interpretation sug- 

 gested above. I must therefore briefly refer to my field of observa- 

 tion in order to verify the conclusion which I am, by elimination, 

 forced to reach with reference to these markings, and also to leave 

 room specifically, for the wider or different experience of others in 

 the observation of strand phenomena. In order to find some reason- 

 able interpretation for these Devonian strand marks, many different 

 kinds of coast have come under my examination — the broad and 

 sandy shores and dune strands of bays and gulfs ; mud flats a mile 

 or more across, exposed and covered with every change in the tide ; 

 the short, steep, gravelly strands of rocky promontory fronts ; capes 

 and bays, retreats and endroits where the tidal interval may be slight 

 or the tide waves rush in upon the coast like an army of white 

 horses ; tide-swept channels and broad, flat seabars of the islands, 

 covering scores of square miles, among whose sands the sea breaks 

 its way by inlets and gullies. I believe my experience has been 

 variant and illuminating, much of it coming from intimate examina- 

 tion along several hundred miles of coast line on the shores and the 

 islands of the Gulf of St Lawrence. I should remark further, that 

 in this Gulf of St Lawrence region the tides are, as a rule, heavy ; 

 and heavy tides on strands of sharp angle would have the power, 

 the other conditions being favorable, of producing such strand mark- 

 ings as those under discussion, if such markings could have been 

 made this way. I am not convinced, either from my observation or 

 from the considerable literature which I have been able to consult 

 on the present action of the tides, that these things could have had 

 the indicated origin under the action of such tides as exist today. It 

 may be granted that heavier tides with more powerful undertow 

 might have produced some of these effects. No such tides are now 

 effective or at least no such tidal effects are, so far 'as observation 

 and reading indicate, recorded. The world's tides may, it has been 

 strongly contended, have been heavier in such ancient ages of the 

 earth and so herein may lie a partial, in at least an alternative 

 explanation of these channeled strands. 



Let us now pass to the consideration of the so-called F u c o i d e s 

 g r a p h i c a , the object early illustrated under this name by 

 Vanuxem and by Hall, and which has long been known as eminently 

 chaiacteristic of these sandy Upper Devonian slabs, but whose vege- 

 table nature was never contended for even at the time the name was 



