Chap. XII. 



INHERITANCE. 



17 



next chapter when discussing latent tendencies, we should have 

 to look at the whole case as one of reversion to an enormously 

 remote, lowly-organised, and multidigitate progenitor. 



I may here allude to a class of facts closely allied to, but 

 somewhat different from, ordinary cases of inheritance. Sir H. 

 Holland 40 states that brothers and sisters of the same family 

 are frequently affected, often at about the same age, by the 

 same peculiar disease, not known to have previously occurred in 

 the family. He specifies the occurrence of diabetes in three 

 brothers under ten years old ; he also remarks that children of 

 the same family often exhibit in common infantile diseases the 

 same peculiar symptoms. My father mentioned to me the case 

 of four brothers who died between the ages of sixty and seventy, 

 in the same highly peculiar comatose state. An instance has 

 already been given of supernumerary digits appearing in four 

 children out of six in a previously unaffected family. Dr. 

 Devay states 41 that two brothers married two sisters, their first- 

 cousins, none of the four nor any relation being an albino; 

 but the seven children produced from this double marriage were 

 all perfect albinoes. Some of these cases, as Mr. Sedgwick 42 

 has shown, are probably the result of reversion to a remote 

 ancestor, of whom no record had been preserved ; and all these 

 cases are so far directly connected with inheritance that no doubt 

 the children inherited a similar constitution from their parents, 

 and, from being exposed to nearly similar conditions of life, it 

 is not surprising that they should be affected in the same manner 

 and at the same period of life. 



Most of the facts hitherto given have served to illustrate the 

 force of inheritance, but we must now consider cases, grouped as 

 well as the subject allows into classes, showing how feeble, capri- 

 cious, or deficient the power of inheritance sometimes is. When 

 a new peculiarity first appears, we can never predict whether it 

 will be inherited. If both parents from their birth present 



40 'Medical Notes and Reflections' 

 1839, pp. 24, 34. See, also, Dr. P. 

 Lucas, ' 1'HereU Nat.,' torn. ii. p. 33. 



41 ' Du Danger des Manages Con- 

 VOL. II. 



sanguins,' 2nd edit., 1862, p. 103. 



42 'British and Foreign Medico- 

 Chirurg. Review,' July, 1863, pp. 183, 

 189. 



C 



