NOMADISM, WITH SPECIAL REFERENCE TO HEREDITY. 13 



phenomena in other members of the family. The source of the his- 

 tories is very diverse ; there have been about 40 contributors to the set, 

 including 26 field workers trained to observe and describe, but wholly 

 innocent of the presence of any law in the recurrence of traits in the 

 family history they submitted. The other contributors have, for the 

 most part, merely filled out a schedule of the traits of their own imme- 

 diate families. It is to be said, moreover, in partial explanation of the 

 fragmentary nature of many of the pedigrees, that in no case was it 

 expected that they would be used in a study of nomadism ; the presence 

 of this trait was not particularly looked for nor inquired into; the 

 information was gleaned incidentally in the course of conversations 

 with parents and others concerning the family history. In a word, the 

 data are recorded without possible bias. 



The order in which the histories are here given is one of convenience 

 for further reference. The less complete histories are placed at the end. 

 The reference numbers are to the files in the records of the Eugenics 

 Record Office. Any statement can be immediately checked by this 

 reference to the original source. The abbreviation Sx is frequently 

 used as a symbol indicating uncontrolled eroticism, leading to various 

 unsocial acts in the sex-realm. 



The family histories considered in this section are 100 in number. 

 They might, theoretically, be grouped into 9 classes, as follows: 

 (A) father nomadic and mother either (i) nomadic, (2) non-nomadic 

 but of nomadic stock, (3) non-nomadic and, so far as known, not of 

 nomadic stock; (B) father non-nomadic, and, so far as known of non- 

 nomadic stock, and mother either (4) nomadic, (5) non-nomadic of 

 nomadic stock, and (6) so far as known of non-nomadic stock ; (C) father 

 non-nomadic, but of nomadic stock, and mother either (7) non-nomadic 

 of nomadic stock, (8) of non-nomadic or unknown stock, (9) nomadic. 

 Class 9 happens not to be represented in our histories. In arranging 

 the histories those of class 5 are placed first, as they constitute the most 

 numerous and typical class, containing about 40 per cent of all the 

 fraternities described in the tables and more than three-fourths of the 

 fraternities that are complete enough to give a fair record of the mater- 

 nal side. Next in order follow classes 4, i, 2, 3, 7, 8, and 6, the last 

 class being that which comprises the most fragmentary histories. 



