THE VICTORIAN NATURALIST. 49 



Melbourne was called to mind — for instance, that on which Christ 

 Church, Hawthorn, stands ; the Northcote hill ; the ridge which 

 runs through West Brunswick, Royal Park, North Melbourne, 

 and as far as the Law Courts, which are all capped by gravel 

 beds, which have effectually guarded them from denudation, while 

 the surrounding hills have been greatly lowered or removed 

 altogether. The amount of denudation that this would imply was 

 considerably more than some of the members were prepared for, 

 and I am afraid that some of them remained somewhat sceptical 

 in spite of the arguments employed for their conversion. — -T. S. 

 Hall. 



THE FLIGHT OF SEA BIRDS. 



By H. R. Hogg, M.A. 



(Read before Field Naturalists'' Club of Victoria, Sth June, 1896. ) 



At the meeting of this club on ioth February, 1896, Mr. H. P. C. 

 Ashworth read an interesting paper on the flight of the albatross 

 (printed in the Victorian Naturalist for April, 1896, vol. xiii., 

 page 11). However, in spite of his accurate description of the 

 movements of the bird, deduced from observation of the Shy 

 Albatross (Thalassogeron cautus, Gould) at their breeding station 

 on the Hunter Group of islands in Bass Strait, he appears to 

 come to no very definite conclusion as to its method of pro- 

 pulsion. I venture, therefore, to add a few notes, in which I 

 hope to be able to make clear to you the principles which my 

 own observations, spread over a good many years and the 

 course of numerous voyages, have led me to believe are those 

 which enable not only the powerful albatross, but many other 

 much smaller birds to keep on the wing for days together con- 

 secutively. 



The principle is the same from the albatross to the Cape 

 Pigeon (Daption capensis) and Stormy Petrel (Procellaria fregata), 

 though the smaller the bird the more often it makes use of the 

 ordinary methods of other birds' flight, the reason of which I 

 will try to show you. I include as sea birds those which, having 

 three wing joints, are able to wander long distances from land, 

 as opposed to those dwellers on the coast-line which, having two 

 joints, can only sustain themselves in the air by means of con- 

 stantly flapping their pinions, and therefore with laboured flight 

 soon tire, and have to rest so constantly that they never go far 

 from shore, and when seen by an ocean voyager are an unerring 

 sign that he is nearing land. 



The true sea birds, except during a comparatively short period 

 of the year when they are engaged in the duties of incubation, 

 spend their lives seeking their food over a wide expanse of ocean 

 and more especially affect the colder zones of the unfrozen parts 



