Page:The advancement of science by experimental research - the Harveian oration, delivered at the Royal College of Physicians, June 27th, 1883 (IA b24869958).pdf/42

38 see the full unveiling of Himself in the incarnation of his own Son; ever and anon by fresh direct manifestation adding to that already given; so in nature, we have indications that there has been direct interference with the chain of events; often gradual, sometimes changes of over- whelming force, but all carrying out the scheme of infinite wisdom.

Whilst speaking of the changes in ani- mals, I would advert to those of even greater interest in man. On him more than on any other form of animal life has the influence of modifying circumstances been manifested in altering his character, in raising or lowering his mental endow- ments and even in changing his physical structure. Slowly have these changes been brought about, and at our own day they are seen to be in operation. The climate in which man resides wonderfully reacts upon his physical state; the heat of the torrid zone demands that the system should be- come accustomed to it; the requirements for the maintenance of animal heat are altered, the normal functions are easily