170 NATURAL INHERITANCE. [CHAP. 



the one of an obvious hereditary tendency to disease 

 and the other of the reverse. There are far too many 

 striking instances of coincidence between the diseases of 

 the parents and of the children to admit of reasonable 

 doubt of their being often inherited. On the other hand, 

 when I hide with my hand the lower part of a page such 

 as those in Tables A and B, and endeavour to make 

 a forecast of what I shall find under my hand after 

 studying the upper portion, I am sometimes greatly mis- 

 taken. Very unpromising marriages have occasionally 

 led to good results, especially where the parental disease 

 is one that usually breaks out late in life, as in the case 

 of cancer. The children may then enjoy a fair length 

 of days and die in the end of some other disease ; 

 although if that disease had been staved off it is quite 

 possible that the cancer would ultimately have appeared. 

 I have two remarkable instances of this. In one of 

 them, three grandparents out of four died of cancer. In 

 each of the fraternities of which the father and mother 

 were members, one and one person only, died of it. 

 As to the children, although four of them have lived to 

 past seventy years, not one has shown any sign of 

 cancer. The other case differs in details, but is equally 

 remarkable. However diseased the parents may be, it 

 is of course possible that the children may inherit the 

 healthier constitutions of their remoter ancestry. Pro- 

 mising looking marriages are occasionally found to lead 

 to a sickly progeny, but my materials are too scanty to 

 permit of a thorough investigation of these cases. 



The general conclusion thus far is, that owing to 



