Inheritance of Physical and Mental Traits 



281 



learn to write or to draw, to meet difficult situations by 

 intelligent adjustment, to control the appetites and passions, 

 to appreciate moral r~<"P\ 



ideas. Many persons 'Vl^ 



who are not regarded 

 as feeble-minded have 

 some of these or simi- 

 lar defects; the t>'pi- 

 cally feeble-minded 

 are defective in several 

 or many such mental 

 traits. In what follows I shall use feeble-mindedness in 

 the latter sense. 



From the studies of Dr. Goddard and others, it appears 

 that when both parents are feeble-minded all of the children 

 wiU be so likewise ; this conclusion has been tested again and 

 again (Fig. 91). But if one of the parents be normal and of 



OtD 



9|6 jijV hi^^^ 



' 2 J -9 S 6 7 & 



Fig. 89. — -Pedigree of relinitis pigmentosa 

 (black symbols) in a family described by 

 I\ I ooren . — Nettle ship . 



m n' N^ N^ ©rn (d/tE Et®tE]' ^^ ^'' 



Fig. 90. — Pedigree of a family with deaf mutes (D) in a large proportion of the 

 later generations. 



normal ancestry, all of the children may be normal (Fig. 

 92); whereas, if the normal person have defective germ 



