1846 1878] Mi-' I I I. A N ; I 01 



to the d — d book, 3rd ed., p. 349,' you will find nearly similar letter 507 

 remarks. Hut at p. 22 ol your Address, in my opinion you 

 push your ideas too far.- I cannot think that future ;ists 



would rank the Suffolk and St. G 3 strata as contempo- 



raneous, but as successive sub-stages; they rank X. America 

 and British stages as contemporaneous, notwithstanding a 



percentage of different species (which they, I presume, would 

 account for by geographical difference) owing to the parallel 

 succession of the forms in both countries. For terrestrial 

 productions 3 I grant that great errors may creep in; but I 

 should require strong evidence before believing that, in coun- 

 tries at all well known, so-called Silurian, Devonian, and 



1 '" When the marine forms arc spoken of as having changed simul- 

 taneously throughout the world, it must not be supposed that this 

 expression relates to the same year, or to the same century, or even that 

 it has a very strict geological sense ; for if all the marine animals now 

 living in Europe, and all those that lived in Europe during the Pleistocene 

 period (a very remote period as measured by years, including the whole 

 Glacial epoch), were compared with those now existing in South America 

 or in Australia, the most skilful naturalist would hardly be able to say 

 whether the present or the Pleistocene inhabitants of Europe resemhled 

 most closely those of the Southern hemisphere." Origin, Ed. VI., p. 29S. 

 The passage in Ed. in., p. 350, is substantially the same. 



- Anniversary Address to the Geological Society of London (Quart. 

 Journ. Geo/. Soc., Vol. XVIII., p. xl, 1862). As an illustration of the 

 misleading use of the term "contemporaneous" as employed by geologists, 

 Huxley gives the following illustration : "Now suppose that, a million or 

 two of years hence, when Britain has made another dip beneath the sea 

 and has come up again, some geologist applies this doctrine [i.e. the 

 doctrine of the Contemporaneity of the European and of the North 

 American Silurians : proof of contemporaneity is considered to be estab- 

 lished by the occurrence of 60 per cent, of species in common], in 

 comparing the strata laid bare by the upheaval of the bottom, say, of 

 St. George's Channel with what may then remain of the Suffolk Craj 

 Reasoning in the same way, he will at once decide the Suffolk Crag and 

 the St. George's Channel beds to be contemporaneous; although we 

 happen to know that a vast period ... of time . . . separates the two" 

 {he. (/A, p. xlv). 'this address is republished in the Collected E 

 Vol. VIII. ; the above passage is at p. 284. 



3 Darwin supposes that terrestrial productions have probably not 

 changed to the same extent as marine organisms. " If the Meg "/, 



Mylodon . . . had been brought to Europe from La Plata, without any 

 information in regard to their geological position, no one would have 

 suspected that they had co-existed with sea shells all still living ' 

 {Origin, Ed. vi., p. 298). 



