116 CARNEGIE INSTITUTION OF WASHINGTON. 



has been widely scattered, necessitating outbreeding; (3) the estab- 

 Hshment of a norm, or control, by the complete study of a small New- 

 England township; (4) the inheritance of chronic chorea; (5) the 

 inheritable basis of pellagra; (6) the inheritance of hare-lip in man 

 and animals; (7) the continued study of the families of institutional 

 cases of the insane, feeble-minded, and emotionally uncontrolled. 



The Director has studied all available cases of close inbreeding 

 and their progeny. While the product of the interbreeding of mem- 

 bers of the same fraternity is usually neuropathic, it is hard to deny 

 that this is due to the neuropathic condition of parents whose emo- 

 tions are so uninhibitable. The progeny of mating between more 

 remote relatives (cousins) frequently show no deterioration. These 

 studies form the basis for a criticism of the numerous State laws 

 hmiting marriage selection. 



The study has been made of strains to which belong a number of 

 cases of eroticism and hysterical temper. Both traits appear clearly 

 as Mendelian dominants. In this respect they are like chronic chorea, 

 a condition characterized by uncoordinated movements apparently 

 due to an inability to inhibit muscular contractions. Extensive data 

 secured by one of the field workers of the Eugenics Record Office 

 enable us to trace back the more prominent lines carrying chronic 

 chorea to about six immigrants to North America over 250 years ago. 



The inheritable basis of so many elements of behavior having been 

 demonstrated, it seemed desirable to call attention in a popular 

 article (Popular Science Monthly, July 1913) to the consequences of 

 the fact, in the hope that unnecessary suffering and abuse, through 

 a wrong interpretation of their behavior, might be saved to those 

 whose reactions are atypical. 



ISOLATION OF BIOTYPES, AND SELECTION. 



Results of Selection of Color Pattern in Rats, by W. E. Castle 

 and J. C. Phillips. 



The work of the animal or plant breeder who seeks to create 

 improved stock is largely done by selecting as breeders those indi- 

 viduals that reveal most nearly those characters that he is looking 

 for. But since inheritance is from the germ-cells and since the 

 soma gives only an inadequate and partial indication of the poten- 

 tialities of the germ-cells, it is clear that selection on the basis of 

 breeding capacity must ever be a better method than selection of the 

 appearance, composition, or behavior of the soma of the individual. 

 Historically it appears that progress has, nevertheless, been made 

 by pure somatic selection; and it is important to know the details 

 and results of this method. Our associate. Professor W. E. Castle, 

 has just completed, in collaboration with Dr. John C. Phillips, and 



