214 Canadian Record of Science. 



cracked in some places, allowing portions of the pulp to 

 ooze out — in some of these its lower dark substance, in 

 others its upper and lighter material. The analogy extends 

 no farther, for there is nothing in our withered fruit to re- 

 present the oceans occupying the lower parts of the surface 

 or the deposits which they have laid down. 



Keeping in view these general conclusions, let us now 

 turn to their bearing on the origin and history of the North 

 Atlantic. 



Though the Atlantic is a deep ocean, its basin does not 

 constitute so much a depression of the crust of the earth as 

 a flattening of it, and this, as recent soundings have shown, 

 with a slight ridge or elevation along its middle, and banks 

 or terraces fringing the edges, so that its form is not so 

 much that of a basin as that of a shallow plate with its 

 middle a little raised. Its true permanent margins are com- 

 posed of portions of the over-crust folded, ridged up and 

 crushed, as if by lateral pressure emanating from the sea 

 itself. We cannot, for example, look at a geological map 

 of America without perceiving that the Appalachian 

 ridges, which intervene between the Atlantic and the St. 

 Lawrence valley, have been driven bodily back by a force 

 acting from the east, and that they have resisted this pres- 

 sure only where, as in the Gulf of St. Lawrence and the 

 Catskill region of JSTew York, they have been protected by 

 outlying masses of very old rocks, as, for example, by that 

 of the island of Newfoundland and that of the Adirondack 

 Mountains. The admirable work begun by my friend and 

 fellow-student Professor James ISTicol, followed up by Hicks, 

 Lap worth, and others, and now, after long controversy, fully 

 confirmed by the recent observations of the geological sui'- 

 vey of Scotland, has shown the most intense action of the 

 same kind on the east side of the ocean in the Scottish high- 

 lands ; and the more widely distributed Eozoic rocks of 

 Scandinavia may be appealed to in further evidence of 

 this. l 



1 Address to the Geological Section, by Prof. Judd, Aberdeen 

 Meeting, 1885. According to Rogers, the crumpling of the Appala- 

 chians has reduced a breadth of 158 miles to about 60. 



