356 



EUGENICS 



tions have given data for the practical appHcations of eugenics. An 

 Eugenics Laboratory is located at Cold Spring Harbor, Long Island, 

 under the supervision of Dr. Charles B. Davenport. Research in 

 the science is being carried on there by the most careful specialists. 

 Methods of investigation. — Families of superior ability. 

 Human heredity has not been studied by the experimental method 

 as successfully as animal and plant heredity have been studied. 

 There are three reasons for this failure : (1) The length of life is so 

 long that no investigator can live long enough to study, personally, 

 the heredity of more than two, three, or possibly four generations 

 of a family ; (2) the number of offspring is small and it is difficult to 

 draw valid conclusions from the limited data offered ; and (3) our 



□ o 



TTiale female 



^marr'ia^e line 



o 



cLesceitt line 



\J^ parents 



6 



tw^irLS 



TIT- "Komon figures 

 ^ cttleftinSieate 

 gen.e tt-qX ion s 



^i ' ^TiiloLren. 



?L.lnf 



^ B.ied. in. 

 inpanc;^ 



Arabic fi^ccres 

 xn8Li V i cLtrccI ^ 



|a] H] d] HI [1 H 



N 



E 



alcoholic blinS. d&a^ epileptic 4ftSTfea, insane ixormal tubercular 



The Eugenics Record Office at Cold Spring Harbor has adopted a standard set of symbols 



used in chart making. 



social customs handicap the work in this research, as people con- 

 sider family affairs private and will not give information freely. 



