Revietvs — Jenkins' Hypothetical Continents. 467 



thus summarily disposed of. As to the exact course of creation, 

 either it Ibelongs not to things revealed, or we have not the reve- 

 lation, or cannot yet coi'relate it. 



V. — The iNTELLECTUAii Observee, for September, 



CONTAINS, among other articles of general interest, one which 

 has so important a geological bearing, that we cannot neglect 

 to call attention to it here. 



The article is by Mr. Henry M. Jenkins, F.Gr.S., the Assistant 

 Secretary to the Gleological Society of London, and is entitled' 

 " Hypothetical Continents." The author, after explaining the nature 

 of the two prevalent theories respecting the origin of organic beings, 

 1, that of their having been created in the several areas they are' 

 found to occupy ; and, 2, the derivative origin of every group by 

 descent with modification from some pre-existing group, assumes as 

 a postulate the truth of the latter theory. He does not adduce facts 

 and arguments in its favour ; but only mentions that compulsory 

 wandering, or " migration," as it is termed, is one of them, and the 

 one that most concerns the su.bject of his article. 



Bearing these two points in view, the palEeontologist can fre- 

 quently infer the progenitors of any particular assemblage of animals 

 or plants, and the route by which their ancestors travelled from 

 their own habitation to that of their more recent descendants. But 

 Mr. Jenkins admits that in tracing the arigin of terrestrial life the 

 paleeontologist meets with some serious difficulties ; but it is gene- 

 rally as to the route which the ancestors of the species have taken; 

 The author points out, that in past time the same laws of climate, 

 and hydrographical and physical conditions produced corresponding 

 changes in the faunas and* floras of the regions affected by them, as 

 at the present day. 



Hypothetical continents have been invoked to account for the 

 relationship which exists between the recent or fossil faunas, or 

 floras of distant regions; For instance, the Atlantis theory was 

 framed to accotmt for the preponderance of American types in the 

 Miocene flora of Europe, which it sought to explain by the supposi- 

 tion that there existed during the Miocene period a great island- ^ 

 continent over which the American flora extended to Europe. This 

 theory has received the support of some able naturalists, but has 

 been assailed by others, chiefly on the grounds that it does not 

 explain the presence of a large number of Japanese and other- types 

 in the European Miocene flora ; and that there is no physical 

 evidence of the existence of an Atlantic continent at so recent a 

 period. 



Mr. Jenkins, after giving a resume of the characters of the Swiss 

 Miocene flora, proceeds to state his objections to the Atlantis theory 

 as hitherto enunciated, and then propounds a modification of it which 

 he conceives more in accordance with the facts to be explained, and 

 not obnoxious to the physical objection urged against the Atlantic 



