Harry Roberts, Everyman in Health and in Sickness, Londres, J.M. Dent, 1935.

Man is not the only animal that clothes itself artificially. The humble caddis worm constructs for itsel a costume as elaborate in its way as any to be seen at a royal reception. But the dress of the caddis worm and of other tailoring animals is pratically constant from generation to generation. No variations are introduced to meet new circumstances or news emotional demands. Man is the great experimenting animal ; he is always trying something fresh..