THE INHERITANCE OF FAMILY TRAITS 101 



g. M^ni^re's Disease is apparently due to a disturbance 

 in the auditory nerve or its centre. It is accompanied 

 by dizziness and roaring in the ear, often so severe as to 

 force the patient to fall to the ground. Sinion (1903) de- 

 scribes a family with these sjonptoms, consisting of an af- 

 fected father, son and two daughters. The onset of the 

 attacks varied from the 25th to the 50th year. 



h. Chorea (St. Vitus's dance) is a disease of the cere- 



I 



n 



ID 



_ II 2l 3. 



jy «n t convulsions 



Fig. 66. — Pedigree of chorea (black symbols). II, 1, became affected with 

 chorea at 8 years before his death; II, 2, has suffered many years; 4 other 

 brothers and sisters are healthy. II, 3, became sick at 35 and suffered until 

 her death at 46; she also had a marked loss of memory and died in a hospital. 



III, 1, is healthy; III, 2, suffers from severe sick headaches. Ill, 3, has chorea. 



IV, 4, is 11 years old and has been afflicted with chorea and epileptic fits for 

 past 2 years. Her sister is still healthy at 10 years. Jolly, 1891. 



bral hemispheres characterized by involuntary, irregular 

 movements of the limbs or other parts of the body. It 

 commonly occurs in families with neuropathic make-up. 

 Ordinarily the disease appears in the children and ends in 

 recovery; occasionally it appears only later in life and runs 

 various courses, sometimes ending in death through exhaus- 

 tion. This disease is commonly sharply separated from 

 Huntington's chorea, but transitional conditions occur. 

 A case cited by Jolly is shown in Fig. 66. In this case noth- 

 ing is known about the first generation; the second com- 

 prises 4 normals and 3 affected persons, 2 males and 1 



