150. THE AUSTRALIAN NATURALIST. 
The geographical distribution was first dealt with, and it 
was stated that for practical commercial purposes the oyster 
was found to be distributed from about Gladstone, Queensland, 
on the north, to a little beyond New South Wales on the south. 
As regards local dispersal, the oyster was usually found in 
esturine and harbour waters from about one-third tide (ebb), 
downwards. The zone was very limited in parts, but where 
the water was suitable, oyster beds might be continuous 
right down to a depth of three or four fathoms or even more. 
- Mr. Stead stated that the oyster attained its greatest perfection 
in size and quality in the vicinity of (but not necessarily on) 
muddy bottoms, and that its local distribution was governed 
by various conditions, chief among which were the density of 
the water and suitability of the bottom. The anatomy was 
next discussed, as well as the food, and its method of obtaining 
the latter, reproduction, and the development from the ege 
onwards. As an illustration of the enormous fecundity of the 
oyster, the lecturer stated that if the progeny, for one season, 
of a pair of moderate sized New South Wales oysters were to 
attain maturity, and their progeny likewise, the product would 
be sufficient to cover an area larger than that of New South 
Wales (309,175 square miles). This led naturally to the dis- 
cussion of the agencies at work in keeping down these numbers ; 
which were, no doubt, in fact, the reason of this productiveness. 
Among the besetting influences at the outset were unfertilized 
eggs, unsuitable water and “ catchment,’ and microscopic 
enemies. Afterwards came the fishes, boring mollusks, star- 
fishes, worms, boring sponge and others. Then there were 
passive resisters, such as marine growths of various kinds 
which enveloped. the oyster. 
Mr. Stead also referred to oyster culture as it exists on the | 
coast of New South Wales, as well as in America and Japan. 
The lecture was interspersed throughout with many beautiful 
and instructive lantern slides. 
REPORTS OF EXCURSIONS. 
Trip TO KILDARA. 
Ocroper.—The monthly excursion was held on Saturday 
afternoon, the 10th October, to Killara, under the leadership of — 
Mr. Waterhouse and myself. Mr. Waterhouse met about 
25 members and friends at the station, and pointed out a 
nesting site of the little diamond bird in a stump hole at the 
top of the cutting in which the station is placed. The birds 
were busily engaged in feeding young. A short stop was made 
at my house, where the birds whose nests we were to inspect 
were laid out, together with their eggs; the party then pro- 
ceeded to the bush. Immediately below my house a half-built 
