THE AUSTRALIAN NATURALIST, 115 
for colouring the exterior of cheeses. The purple colour 
changes to red under the action of acids in the cheeses. 
Miss A. A. Brewster exhibited (with note) galls of Apzo- 
morpha duplex from Homebush Bay. ‘The life history of the 
insects at various stages was depicted in a series of excellent 
drawings. An interesting discussion on the Cultivation and 
Protection of the Native Flora was opened by Mr. EH. Cheel, 
followed by Mr. W. M. Carne, Mr. Luke Gallard, and other 
members. Mr. A. C. Duckworth gave a list of native plants 
successfully transplanted, with notes on the methods adopted. 
PRESIDENTIAL ADDRESS, AUGUST, 1919. 
THE SCIENTIFIC STUDY OF SCENERY. 
With Particular Reference to The Grand Canyon, Blackheath. 
By F. W. Carpenter, M.A. 
This address was planned as a lantern lecture arranged so 
that the photographs might tell their own story. Possibly the 
following notes written at sea, away from my photographs and 
even my field note-book, may be of value to those who ean visit 
the Canyon. ‘ 
The photographs were selected to prove that the Grand Can- 
yon was ‘eroded by water action, similar in kind to that which 
is still going on after every rainstorm; quite unaided by the 
sary. A diagram was shown of block faulting—a well-known 
and well-accepted explanation of a few of the great river valleys . 
of the world; but it is necessary to add that these fault riven 
valleys are on a seale far exceeding the valley which we are dis- 
cussing, especially in the matter of breadth. 
The notable features of the Blue Mountains are the flatness 
of the mountain top, and the precipitous nature of the walls of 
-the numerous gullies. The geological map shows that the 
Mountains are a highly dissected plateau; which owes its flatness, 
both to the horizontal nature of the strata of which it is com- 
posed, and to the fact that it had been denudéd to a plain before 
the great uplift that gave it its present level. The view from 
vans’ Lookout shows these features clearly. The long stretch 
of vertical cliff of Hawkesbury sandstone is capped by a bed of 
more cataclasmic agencies which so many laymen think neces- 
exceptional hardness, which shows jointing on a most massive 
