88 Hypothetical Continents. 



HYPOTHETICAL CONTINENTS. 



BY H. M. JENKINS., F.G.S. 



The present surface of the globe has admitted of division into 

 several marine and. terrestrial regions, each characterized by 

 ita inhabitants possessing, as a whole, more or less distinctive 

 features ; just as, on the principle of nationalities, we might 

 divide Europe, Asia, and Africa into several natural kingdoms. 

 This division has involved, no theoretical considerations of any 

 importance, and it is only when an attempt is made to explain 

 the origin of the inhabitants of any particular area that the 

 naturalist ventures to step beyond the region of unyielding 

 facts, and addresses himself to the more pliant province of 

 hypothesis. The palaeontologist, also, frequently seeks to 

 trace the origin of ancient faunas and floras, and finds assist- 

 ance in comparing the population* of bygone periods with that 

 now peopling the earth's surface in the same, or neighbouring, 

 or distant areas. And as, in searching for the origin of things, 

 we must necessarily go back to some previous period, his 

 palaeontological knowledge specially fits him for the task, on 

 account of his being acquainted with those facts, the ignorance 

 of which not unfrequently forces the student of recent nature 

 into the wilderness of pure hypothesis, or even imagination. 



Two theories are prevalent respecting the origin of organic 

 beings in particular areas. The first of these is that the fauna 

 and flora of each great area possess, as a whole, certain distin- 

 guishing characteristics which belong to that district alone, and 

 have never been disseminated through other regions ; and that 

 the species composing the population of that area have been 

 created from time to time, probably as representative species 

 died out. The opposing theory is that of the derivative origin 

 of every group of organisms, whether species, genus, etc. ; in 

 other words, that each species is the modified descendant of 

 some other species of the same genus, until the successive 

 modifications cause so wide a divergence from the type, that a 

 modified form transgresses the conventional circle which we 

 draw round the generic type, and thus causes us to refer it to 

 another genus. 



It is quite obvious that if the first theory be true, any 

 attempt to trace the origin of the present and past faunas and 

 floras must necessarily be completely futile ; for have we not 

 their origin sufficiently elucidated in the dogma that "they 



* Tho use of the terms " population," " peopling," etc., is in this paper 

 restricted to the animal and vegetable "population," and is not meant to include 

 man. 



