THE CAUSATION OF DISEASE. 7 7 



affect different tissues. Father remarkable for mus- 

 cular strength, mother for intellect. In one sense 

 this comes under the last head (lb), for there is a 

 blending of remarkable with ordinary muscular 

 strength, and a blending of remarkable with ordinary 

 intellectual powers. 

 2b. One of the blending characters is -normal, the other 

 abnormal, and they affect the same tissue. The 

 mother is emmetropic, the father hypermetropic. All 

 abnormal blendings resulting from the union of a 

 healthy with an unhealthy parent are of this kind. 

 yi. The blending characters are abnormal, of the same kind, 

 and involve the same tissues. The father and mother 

 are gouty, rheumatic, neurotic, or what not. 

 3&. The blendings are abnormal, affect the same tissue, but 

 are of unlike kind. Thus the father is myopic, the 

 mother hypermetropic. The father suffers from a ten- 

 dency to eczema, the mother to psoriasis. In such a 

 case one would theoretically expect a hybrid or mongrel 

 disease to result. 

 3c. The blending characters are abnormal, but unlike, and 

 affect different tissues. Thus the father is gouty, the 

 mother epileptic — the father rheumatic, the mother 

 phthisical. Here, again, the possibility of hybridiza- 

 tion arises. 

 It will be necessary now to consider these classes more in 

 detail. 



1 a. Like physiological blending of the same tissue. — Here, of 

 course, the offspring will tend to inherit the peculiarity in 

 undiminished vigour — as when, for instance, both sides of the 

 house are remarkable for strength of muscle. In such a case 

 there is no reason why the offspring should be muscularly 

 weaker than the parents ; nor is there any reason why they 

 should be stronger — why, namely, there should be any intensi- 

 fication of the peculiarity, although one is rather apt to assume 

 such an intensification. 



lb. The blending of unlike normal characters affecting the 

 same tissue. — If each parent present a different physiological 

 peculiarity of the same tissue, one would expect the blending 



