38 INHERITANCE, VARIATION AND SELECTION. 



In the cases of insanity Philips gives, from 117 insane males, 

 64 inherited from the father and 53 from the mother. For 147 

 insane females, 80 inherited from the mother and 67 from the 

 father. In cases of consumption recorded by Lugol, of 106 con- 

 sumptive males, 63 inherited the disease from the father and 43 

 from the mother. Of 108 consumptive females, 61 inherited the 

 disease from the mother and 47 from the father. 32 



Speaking of skin diseases Mr. Sedgwick says : 33 "In some 

 of these cases it is recorded that, while the males alone have suf- 

 fered from the disease, the females alone have been able to transmit 

 it, as in the case of Mr. Appleton, whose daughter conveyed the 

 complaint to his grandsons, and who, in turn, transmitted it 

 through their daughters to their grandsons ; the males in this fam- 

 ily, as in many others similarly affected, never inheriting the disease 

 from the fathers, but always through females from their grand- 

 fathers." 



INHERITANCE AT CORRESPONDING AGES. 



Not all characters which are transmitted from parent to child 

 are present in the child at birth, but appear at some later stage. 

 In such cases the tendency is for the character to appear in the 

 offspring at the same age that it first appeared in the parent. This 

 rule includes nearly, if not all, secondary sexual characters, which 

 usually appear near the age of maturity, as in the case of beards 

 on men and the change of voice which occurs at puberty. Certain 

 breeds of pigeons do not acquire their characteristic colors until they 

 have moulted two, three or four times; and these modifications of 

 plumage are regularly transmitted. 34 In the diseases like gout, apo- 



(32) Quoted by Miles in "Stock Breeding." 



(33) British and Foreign Medico-Chirurgical Review, 1861, p. 246. 



(34) Descent of Man, Vol. I, p. 272. 



