2 Eugenics Record Office, Bui.i,etin No. 4 



due to it. These pedigrees were collected in major part 

 by Mrs. D. Leucile Field Woodward, of the Skillman Village, 

 and in minor part by Miss Saidee C. Devitt, of the Eugenics 

 Record Office, while assigned to that village. These women 

 visited the homes of patients, interviewed parents and other rela- 

 tives, and physicians for the purpose of securing an accurate 

 account of the mental history, environmental conditions, diseases 

 and causes of death, if dead, of as many relatives as possible of 

 the patient. The pedigree data thus obtained have proved to be 

 much more significant and trustworthy than the familiar " family 

 histories " commonly obtained from the patient or his guardian at 

 the time of admission. Our data, we are convinced, approximate 

 closely enough to the truth to warrant careful study, which is 

 more than can be said for the ordinary " family history." 



The number of separate pedigrees used in the present study 

 has been 177. Two of these pedigrees were found to be con- 

 nected with pedigrees that had been acquired earlier, so that 

 there are only 175 separate families involved, and there is little 

 doubt that further study will show some of these to be of the 

 same blood. The number 175 gives no idea of the number of 

 epileptics recorded in the pedigrees, since as many as 4 have been 

 described in a single fraternity (full brothers and sisters), and 

 several fraternities with epileptic individuals have been described 

 in the same pedigree. In the tables that accompany this paper 

 a single pedigree chart has sometimes yielded more than a single 

 entry ; on the other hand the data from 23 pedigree charts were 

 altogether excluded because the mental condition of one or both 

 parents of the principal fraternity was not ascertained by the field 

 worker. The number of fraternities eventually considered in 

 the following tables (each presumably descended from a single 

 pair of parents) is 181. The total number of epileptics in the 

 fraternities analysed is 206, but there were many other epileptics 

 recorded in the charts who could not be used for study because 

 of the fragmentary knowledge of their parentages and their sibs 

 (i. e., brothers and sisters). 



3. The Method of Analyzing the Data 

 This differs from that commonly employed hitherto in studies 

 on the inheritance of human defects and diseases. Until recently 

 it has been considered sufficient to determine in what proportion 



