DOMESTICATED INSECTS 251 
the question of evolution. The various breeds were studied 
with the utmost thoroughness by Darwin, and more recent ob- 
servations show that the subject is by no means exhausted, and 
that these birds are most desirable subjects for experiment when 
heredity problems have to be considered. 
Tue Arrican OstTRIcH (STRUTHIO caMELUs).— Although 
ostriches have been domesticated or semi-domesticated by some 
of the native tribes of Africa from remote times, the “ostrich 
farms” of the south are of comparatively recent date (fig. 1182). 
The inducement to this industry is of course found in the valu- 
able plumage, the white wing-feathers being most esteemed, 
while those of the tail and also some of the back plumes are 
also marketable. Birds are in their prime when from three to 
four years old, and the feathers of the males are of better 
quality than those of the females. They are plucked or cut off 
about twice in three years, and are subjected to a number of 
processes before being fit for use. Ostrich-feathers constitute an 
important export from Cape Colony, yielding not far short of a 
million pounds sterling annually. The industry has been intro- 
duced with more or less success into several other parts of the 
world, notably Southern California and Australia. 
DOMESTICATED INSECTS (INSECTA) 
Under this heading may be placed the Honey-Bee (AZzs 
mellifica), the Silk-Worm Moth (Bombyx mori, &c.), and the 
Cochineal Insect (Coccus cactz). The industries which these 
insects render possible are all of ancient date, and the two first 
of very considerable importance. 
Tue Honey-Bee (Apis MELLiFIcA).—A liking for sweet 
things is a wide-spread human weakness, and appears to be of 
very old standing. Wild bees of different kind are native to 
many parts of the world, and the honey which some of them 
store in abundance no doubt soon attracted the attention of 
primitive peoples, whose most important business in life con- 
sisted in the discovery of edibles (compare vol. ii, p. 63). Of 
a small Brazilian species Bates says (in Zhe Naturalist on the 
Amazons):—‘‘ A hive of the Melipona fasciculata, which I saw 
opened, contained about two quarts of pleasantly-tasted honey. 
The bees... have no sting, but they bite furiously when their 
