ANNIYEESARY ADDRESS OF THE PRESIDENT. 69 



phj'-sical and chemical laws in other and far distant orbs, so 

 Palaeontology presents us with the Biological phenomena of many 

 and widely-separated periods. 



But besides the biological, there are two other aspects in which 

 fossils may be viewed ; and in these aspects their relations are almost 

 entirely with geological science. It is the recognition of this fact 

 which prevents the Geologist from acquiescing in the claim of 

 Biologists to treat Palseontology as nothing more than a branch of 

 their own science. 



The assemblage of fossils found in a particular deposit furnishes 

 us with the most valuable evidence concerning the conditions — such 

 as salinity of water, depth, temperature, pressure, &c. — under which 

 the deposit must have been formed. And, again, in the changes 

 which the materials of fossils can be shown to have undergone we 

 have very accurate data for determining the succession of processes 

 which the materials of the deposit must have been subjected to since 

 their original accumulation. 



It is true that this evidence of fossils concerning the conditions 

 under which deposits have been formed is of a kind which has been 

 sadly misread in the past. Until the study of deposits which are being 

 formed in the existing seas was taken up in a systematic manner, 

 it was almost hopeless to avoid numerous sources of error ; but at 

 the present day the advantages accruing to Geology from the results 

 of deep-sea researches are at least as great as those which by the 

 same means have been conferred upon Biology. 



It is almost needless to call attention to the fact that there are 

 vast masses of rock, including most of the calcareous and carbon- 

 aceous, and many of the siliceous and ferruginous types, of which 

 the materials have been accumulated entirely by the agency of 

 living organisms ; and it is impossible to study the petrology of such 

 deposits without an acquaintance with the nature and functions of 

 the organisms by which they were formed. But, even in the 

 case of many arenaceous and argillaceous deposits, living organisms 

 have played a very important part in their formation. Much of the 

 materials of such rocks can be shown to have at one time formed 

 part of the external skeletons of organisms, to have filled up their 

 dead shells, or to have been passed through their bodies — before 

 being finally buried under other masses. Eocks destitute of all 

 other traces of animal life often abound with worm-tracks, burrows, 

 or casts. 



The study of the processes by which similar formations are being 



