PRESIDENTIAL ADDRESS. 15 



Australian Museum for study, and a couple of volumes of 

 valuable zoological reports on them have been already- 

 issued by the Federal Government. But important reports 

 which Mr. Dannevig was preparing on the physical con- 

 ditions of the continental shelf have unfortunately dis- 

 appeared with him and his vessel. He published in our 

 forty-first volume an article "On Some Peculiarities in 

 Our Ooastal Winds and Their Influence upon the Abund- 

 ance of Pish in Inshore Waters." 



For the scientific portion of the address the following 

 subject is chosen for discussion because it has been, hitherto, 

 but little cultivated. 



An Ecological Sketch of the Sydney Beaches. 



SYNOPSIS : 



Introduction. 



Environment — Ground, 



Temperature, 

 Salinity, 

 Tides. 

 Comparison of Local and Foreign Fauna. 

 Changes op Climate and Time. 

 Changes by Epidemics and Accidents.* 

 Transition prom Marine to Terrestrial. 

 Types of Beaches — Shingle beach, 



Ocean sand beach, 

 Estuarine beach, 

 Ocean reef beach. 



Introduction. 

 Marine ecology, that is the relation of marine organisms 

 to their surroundings and to one another, is undeveloped 

 in comparison with terrestrial ecology, because our know- 

 ledge of the life history and physiology on which such 

 studies depend is deficient. Yet exceptional advantages 

 are offered to the Sydney naturalist, because a variety of 

 stations ranging from fresh water to salt, from rock to 



