THE GEELONG NATURALIST. 3 
The back is a dull slate colour, but takes its name from a brown 
band or collar, extending around the back of the neck. Its habits 
are much like those of the Australian Gosé-iawk. I forgot to 
mention that some of the wing covers are spotted with white, but 
this is not noticed unless the wing is extended. Although this bird 
has not got the expanse of wing of some of the Falcon tribe, it is 
remarkably swift and determined in pursuit of its prey, as many 
farmers find to their cost when they have chickens about. Although 
he takes toll from the farmers, he more than pays for what he takes 
in destroying the grain-feeding birds, mice, and young rabbits. 
The bird I described had its gizzard filled with rabbit’s hair. This . 
proves this hawk is a friend to the agriculturist, and should be 
protected, The Collared Gos§ Hawk is common in the Cape 
Otway and this district, but seems to prefer the timbered land. It 
builds a rough nest on moderately high trees, and lays. 3 or 4 eggs, 
but I am doubtful if it rears the number of young. ‘The eggs are 
a little larger than the kestrel’s, white, with reddish brown spots, 
and blotches the same, very wide apart. Thereis a great difference 
in size of the sexes, the male being a great deal smaller than the 
female. J. F. MULDER, 
WOOL. 
Woor is the most important of all animal substances used in 
manufacture, and ranks next to cotton as a raw material for tex- 
tile fabrics. It is a variety of hair. The term hair is generally 
applied to a smooth, straight filament like human or horse hair. 
Wool, on the other hand, is always more or less waved, and 
externally each filament is seen under the microscope to be 
covered with overlapping scales, which project whenever a bend 
occurs in the fibre. ‘This causes the fibres to become entangled in 
spinning. 
The serrated structure gives Wool the property of felting, 
upon which many of its applications depend. It also possesses a 
softness of touch and an elasticity which distinguishes it from. all 
other fibres. 
Wool varies accordine: to the peculiar breed of sheep which 
yields it, and also with the food, shelter, and climate. It gene- 
rally comes into the market in the form of fleece wool. The 
younger sheep generally produce a fibre longer in the staple and 
consequently of a better quality. The sheep is by no means the 
only animal which yields wool employed for industrial purposes, 
but it is the most important From the ease with which it is 
made into woollen clothing, it would naturally be used very early 
by the human race. The sheep was a domestic animal in England 
