STATEMENT OF PROBLEM. 23 



Maranon and Bonilla I L920) cite the ca» of a girl of is years who 

 was slender, like her parents, until after an attack of Byphilis, when 

 she came to weigh 157 kg. or 350 pounds, while her height was 160 

 cm., her chest-girth 130 cm., and that of her abdomen L50 cm. oi 90 

 per cent of her height. She had a very large brother, and both 

 mother's parents were obese, though the parents were not known to 

 be so. 



Such examples might be multiplied indefinitely. 



Our problem is not what arc all the causes of this diversity <»t' build, 

 but rather in how far do genetical factors play a part in this diversity. 

 We are not oblivious to the fact that there are many factors responsi- 

 ble for the result — deviation from the average build. These we -hall 

 consider in detail in a later section, and the consideration will help 

 us to see the limits to the action of the genetical factors. Before going 

 on to that, we shall have to consider more in detail the nature of the 

 facts for which an explanation has to be sought. 



METHODS AND MATERIALS. 



The method of analyzing the genetic factors in build is that of 

 tabulating the distribution of aberrant builds in the family network. 

 There is required, first, a large mass of family data which includes 

 many extreme or aberrant types of build, and which is as reliable and 

 as accurately quantitative as possible; secondly, this has to be sub- 

 jected to the ordinary methods of genetic analysis. 



The available material has consisted of data on stature and weight 

 given in the Records of Family Traits which constitute a fair sample 

 of the population; and of quantitative data on special schedules 

 giving stature and weight of a fraternity, its parents, uncles and 

 aunts, and grand-parents. These special schedules had been mailed 

 to an address list of overweight and underweight persons obtained 

 through the kind cooperation of Mr. Arthur Hunter. Those who 

 returned the schedules showed an especial appreciation of the require- 

 ments of our study. A third source w T as the A file of the Eugenics 

 Record Office, where are gathered miscellaneous pedigrees <»t families 

 showing aberrancy in build. A fourth and especially valuable source 

 was the field work of Miss Louise A. Nelson, of the Eugenics 1!' cord 

 Office; this started with selected, usually obese, cases. 



After the data had been assembled and tabulated, a certain amount 

 of correspondence and personal visitation was undertaken m cider to 

 secure a confirmation or revision of the records in hand. In some 

 cases this brought to light errors in the records, in others LSeful 

 details. Naturally, it was not possible t<> Becure a revision of all of 

 the data used, but an attempt was made to select only records that 

 had been compiled with care and conscientiousness, and these traits 

 in the compiler reveal themselves pretty clearly to a person who I 



