THE INHERITANCE OF FAMILY TRAITS 97 



insane or epileptic children. One sees what a variety of 

 gametic conditions may be carried by a ''nervous" or 

 even a ''normal" person, just as blue eyes may be carried 

 by brown eyed parents, or Hght pi_^ 

 brown hair by dark haired parents. 

 A ''nervous" person is thus fre- 

 quently simplex in the factor that 

 makes for mental strength and is 

 apt to carry defective germ cells 

 (Figs. 57-59). 



Dh8) 



t&if 





c. Cerebral Hemorrhage. — How- 



Fig. 57. — Pedigree o f 

 ,, ii . nervous trouble." 1, 2, was 



ever numerous the causes that typically affected and i, 4 

 weaken the walls of the cerebral suffered from migraine, ii, 



1, had the same nervous trou- 



arteries or raise abnormally the ble. Of three grandchildren 

 pressure upon them, there can be ^^^/^^ve, i already shows 



^ ^ ' ^ at 6 years, a tendency to- 



little doubt that hereditary predis- ward nervous weakness. F. 



position plays an important part. ' ^^' " 



(Figs. 60 and 61). Cerebral hemorrhage is commonly 



found in the parentage or grandparentage of the mentally 



I 'Dp b^ 



M 



b %hb ffi*&6 '6 '6 



Fig. 58. — Inheritance of nervousness and brilliancy. I, 4, is subject to 

 headaches and nervousness. Her daughter, II, 7, is similarly affected. She 

 married a man, II, 6, who has had temporary attacks of paralysis. One of 

 their children, II, 2, has nervous prostration and one, III, 3, is subject to head- 

 aches and nervousness. F. R. ; Cla. 3. 



weak as well as brilliant. (Fig. 61), See also arteriosclero- 

 sis, page 162. 



d. Cerebral Palsy of Infancy, — This disease, of obscure 

 origin, affects infants within a few years of birth; it leads 



