Page:The advancement of science by experimental research - the Harveian oration, delivered at the Royal College of Physicians, June 27th, 1883 (IA b24869958).pdf/45

 hardy fisherman and sailor exposed to the vicissitudes of weather and to the storm and tempest, with the man whose life is spent in one close room or for long hours in a poisoned atmosphere. The life is changed, and the consequences are seen in succeeding generations, till the whole race is affected, and the impress is witnessed in the most marked divergence of character, thought and action.

But there is another evolution in man. Morbific changes take place from the result of modifying conditions; an evolution which is the direct result of pathological states. The parent may be affected with syphilis, and the offspring becomes altered in its whole development and growth, and if beside one or both parents have a strumous or scrofulous diathesis, or have shewn a proneness to cancerous disease, the state of the offspring is modified still further; or with a tendency to gout another force is presented, and the resultant is an altered phase of life. Still further, the parent may have a nervous system that is extremely sensitive and easily disturbed; it may be