President's Address. 5 



Palaeozoic Mediterranean Sea, may rather afford some 

 indication of the direction in which a current from the 

 warm south-west flowed eastward over what is now the 

 centre of Europe. 



4. A fourth contribution to geology, from recent investiga- 

 tions into the zoology of the sea, relates to the manner in which 

 coral-reefs have been formed. I shall endeavour to show, by 

 a detailed statement of this case, how deep is the debt that 

 geologists owe to the naturalists of those great exploring 

 expeditious which have been so marked a feature in the 

 scientific research of the last decade. 



So much additional information has in recent years been 

 obtained regarding the physical and biological conditions of 

 the sea, that such a problem as that presented by the coral- 

 islands of mid-ocean may well be reconsidered. Several able 

 naturalists have lately called attention to this problem, and 

 have insisted that the generally-received solution of it is not 

 satisfactory. Among geologists, there may not unreasonably 

 be a good deal of unwillingness to admit that this contention 

 can be well founded. They have long been accustomed to 

 regard Darwin's theory of coral- formation with justifiable 

 pride, as a masterpiece of exhaustive observation and brilliant 

 generalisation. It has played an important part in their 

 speculations regarding the larger movements of the earth's 

 crust, and they have been so deeply impressed with its 

 simplicity, and the grandeur of the conclusions to which it 

 leads, that they will naturally and rightly refuse to surrender 

 any i3ortion of it save under the strongest compulsion of 

 evidence. Some, indeed, may be inclined even to resent, 

 almost with the warmth inspired by a personal injury, any 

 attempt to show that it can no longer claim the general 

 applicability which has been regarded as one of the strongest 

 arguments in its favour. But the example of Darwin's own 

 candour and over-mastering love of truth remains to assure 

 us that no one would have welcomed fresh discoveries more 

 heartily than he, even should they lead to the setting aside 

 of some of his own work. I propose to give here, somewhat 

 in detail, the more important data accumulated in recent 

 years on this subject, and to state the conclusions to which a 



