ciiAr. VI.] GEOGRAPHICAL AND GEOLOGICAL CHANGES. 101 



Summary of Evidence for the General Fermanence of Co7itinents 

 and Oceans. — As this question of the permanence of our 

 continents lies at the root of all our inquiries into the past 

 changes of the earth and its inhabitants, and as it is at present 

 completely ignored by many writers, and even by naturalists of 

 eminence, it will be well to summarise the various kinds of 

 evidence which go to establish it.^ We know as a fact that all 

 sedimentary deposits have been formed under water, but w^e 

 also know that they were largely formed in lakes or inland 

 seas, or near the coasts of continents or great islands, and that 

 deposits uniform in character and more than 150 or 200 miles 

 wide were rarely, if ever, formed at the same time. The further 

 we go from the land the less rapidly deposition takes place, 

 hence the great bulk of all the strata must have been formed 

 near land. Some deposits are, it is true, continually forming in 

 the midst of the great oceans, but these are chiefly organic and 

 increase very slowly, and there is no proof that any part of the 

 series of known geological formations exactly resembles them. 

 Chalk, which is still believed to be such a deposit by many 

 naturalists, has been shown, by its contained fossils, to be a 



^ In a review of Mr. Reade's Chemical Denudation and Geological Time 

 in Nature (Oct. 2nd, 1879) the writer remarks as follows : — " One of the 

 funny notions of some scientific thinkers meets with no favour from Mr. 

 Reade, whose geological knowledge is practical as well as theoretical. They 

 consider that because the older rocks contain nothing like the present red 

 clays, &c., of the ocean floor, that the oceans have always been in their 

 present positions. Mr. Reade points out that the first proposition is not 

 yet proved, and the distribution of animals and plants and the fact that 

 the bulk of the strata on land are of marine origin are opposed to the hypo- 

 thesis." We must leave it to our readers to decide whether the " notion " 

 developed in this chapter is " funny," or whether such hasty and superficial 

 arguments as those here quoted from a " practical geologist " have any 

 value as against the different classes of facts, all pointing to an opposite 

 conclusion, which have now been briefly laid before them, supported as 

 they are by the expressed opinion of so weighty an authority as Professor 

 Archibald Geikie, who, in the lecture already quoted says: — "From all 

 this evidence we may legitimately conclude that the present land of the 

 globe, though formed in great measure of marine formations, has never 

 lain under the deep sea ; but that its site must always have been near 

 land. Even its thick marine limestones are the deposits of comparatively 

 shallow water." 



