ANNUAL ADDEESS TO THE MEMBERS 



OF THE 



SOUTH AFRICAN PHILOSOPHICAL SOCIETY 



On August the 17th, 1904. 



By the Peesident, J. D. F. GILCHRIST, M.A., Ph.D. 



SOME FEATURES OF THE MARINE FAUNA OF 



SOUTH AFRICA. 



Following the example of former Presidents of the Philosophical 

 Society, an example which our esteemed Secretary who has long 

 been associated with the Society assures me has now acquired the 

 authority of a rule, I shall endeavour to lay before you to-night a few 

 of the outstanding features and facts in connection with a subject in 

 which I have been more particularly interested. It is a subject 

 which in the past has not received the amount of attention that 

 its peculiarly interesting character merits, and it would be premature 

 now to formulate any sweeping and definite generalisations which 

 a fuller knowledge of facts will yet make possible. There are, how- 

 ever, certain well-ascertained facts and certain general features 

 which are becoming apparent, and it may not be without interest 

 to present these in the form of a brief summary. 



I will draw your attention in the first place to what may be 

 regarded as the feature of the Marine Fauna of South Africa, or 

 rather the key to the whole character of this fauna. It would 

 apparently be a wild statement to say that this is intimately 

 associated with the rise and fall of the barometer, but I hope to 

 show you that this is to a large extent the case, and I put it in this 

 way in order to emphasise the special features I wish to bring to 

 your notice. 



We know that all forms of animal life are intimately asso- 

 ciated with their environment or the environment of their 

 ancestral forms, and we readily understand how in the case of 

 terrestrial animals the physical factors in operation, for instance, 

 in the forest, in the desert, or in arctic regions, demand a strict 



