162 PROCEEDTNOg OF THE GEOLOGICAL SOCIETY. 



parts were deposited as we can discover in the slates of Wales and 

 of Westmoreland. 



We have received as yet only a part of the results of the labours 

 of Professor Forbes, and wait with impatience for his greater work ; 

 but what he has already made known to us of the changes that take 

 place in organized bodies in different zones of depth, and in different 

 states of sea-bottom, have so extensive a bearing upon many of the 

 inferences hitherto drawn as to the ages of deposits, and to changes 

 of climate from fossil contents, that some of our most established 

 doctrines ought to be revised, and their soundness tested by their ac- 

 cordance or otherwise with these conditions. Others hypothetically 

 anticipated that rocks might have been formed in depths unsuited 

 to animal and vegetable life ; but Professor Forbes was the first, 

 I believe, to establish by actual observation that such is the 

 fact as to depth, and also the first to show, as an element of geolo- 

 gical reasoning, the connection that subsists between the nature of 

 the sea-bottom (often changing on the same spot) and the living 

 bodies it supports, and thus to demonstrate the existence of laws of 

 the highest geological importance, and which must have prevailed 

 throughout the whole range of formations. 



Among the communications read before the Society since the 

 last Anniversary, we have had two by Professor Sedgwick on the 

 comparative classification of the fossiliferous strata of North Wales 

 with the corresponding deposits of Cumberland, Westmoreland 

 and Lancashire, both of them in continuation of his memoir read 

 in November 1843. I will not attempt to give any abstract of the 

 contents of these papers, because I could not do so, to any useful 

 purpose, without extending my observations to an inconvenient 

 length; but I recommend all who are desirous of acquiring an ac- 

 curate knowledge of the geological topography of those parts of our 

 island, and of becoming acquainted with many facts that throw light 

 on that obscure and difficult part of geology, to study the memoirs 

 themselves: those of 184S and of March 1845 are published in the 

 first volume of our Journal, and the last of them will appear in the 

 number of next May*. 



It is to Professor Sedgwick we are mainly indebted for the know- 

 ledge we possess of the geological structure of those parts of our 

 island ; it was he who first grappled with their very complicated 

 and difficult conformation ; for nearly twenty years he has been 

 labouring to decipher their obscure and complex characters ; and 

 since the discovery of the Silurian key, he has been enabled to make 

 out a clear and intelligible outline of the history of these regions, 

 which, for a long time, geologists seemed to shrink from all attempts 

 to understand. Let us hope that the learned author will soon 

 gather together his scattered materials, and bring out a new edition 

 of his work, with all the corrections and illustrations which his latest 

 observations enable him to supply. When we have that volume, 

 and can study it with the commentaries and the additional illustra- 

 tions of accurate sections which we in part have, and may soon 

 * See ante, p. 106. 



