Thorndyke's absorbing interest in the camelidæ seemed now suddenly to become extinct, and he suffered me to lead him to any part of the gardens that attracted me, showing an impartial interest in all the inmates from the insects to the elephants, and enjoying his holiday—if it was one—with the gaiety and high spirits of a school-boy. Yet he never let slip a chance of picking up a stray hair or feather, but gathered up each with care, wrapped it in its separate paper, on which was written its description, and deposited it in his tin collecting-box.
"You never know," he remarked, as we turned away from the ostrich enclosure, "when a specimen for comparison may be of vital importance. Here, for instance, is a small feather of a cassowary, and here the hair of a wapiti deer; now the recognition of either of those might, in certain circumstances, lead to the detection of a criminal or save the life of an innocent man. The thing has happened repeatedly, and may happen again to-morrow."
"You must have an enormous collection of hairs in your cabinet," I remarked, as we walked home.
"I have," he replied, "probably the largest in the world. And as to other microscopical objects of medico-legal interest, such as dust and mud from different localities and from special industries
