PHENOMENA OF INHERITANCE 319 



ness, epilepsy and insanity are inherited, and that there is often a 

 hereditary basis for nervous and phlegmatic temperaments, for emo- 

 tional, judicial and calculating dispositions. Nor can it be denied that 

 strength or weakness of will, a tendency to moral obliquity or rectitude, 

 capacity or incapacity for the highest intellectual pursuits, occur fre- 

 quently in certain families and appear to be inherited. In spite of cer- 

 tain noteworthy exceptions, which may perhaps be due to remarkable 

 variations, statistics collected by Galton show that genius is hereditary; 

 while the work of certain recent investigators, particularly Goddard, 

 Davenport and Weeks, proves that feeble-mindedness and epilepsy are 

 also inherited; and the careful work of Mott and of Eosanoff leaves no 

 room for doubt that certain types of insanity are hereditary. It fre- 

 quently happens that families in which hereditary insanity occurs also 

 have other members afflicted with epilepsy, hysteria, alcoholism, etc., 

 which would indicate that the thing inherited is an unstable condition 

 of the nervous system which may take various forms under slightly dif- 

 ferent conditions. Woods has collected data concerning "Heredity in 

 Royalty " which seem to show that very high or low grades of intellect 

 and virtues may be traced through the royal families of Europe for sev- 

 eral generations. 



The general trend of all recent work on heredity is unmistakable, 

 whether it concerns man or lower animals. The entire organism, con- 

 sisting of structures and functions, body and mind, develops out of the 

 germ, and the organization of the germ determines all the possibilities 

 of development of the mind no less than of the body, though the actual 

 realization of any possibility is dependent also upon environmental 

 stimuli. 



II. Hereditary Differences 



There are many limitations or exceptions to the general rule that 

 children resemble their parents. Sometimes these differences are due to 

 new combinations of ancestral characters, sometimes they are actually 

 new characters not present so far as known in any of the ancestors, 

 though even such new characters must arise from new combinations of 

 the elements of old characters, as we shall see later. 



1. New Combinations of Characters. — In all cases of sexually pro- 

 duced organisms new combinations of ancestral characters are evident. 

 Usually a child inherits some traits from one parent and other traits 

 from the other parent, so that it is a kind of mosaic of ancestral traits. 

 Such inheritance, bit by bit, of this character from one progenitor and 

 that from another was described by Galton as "particulate" (Fig. 47). 

 On the other hand Galton supposed that in some instances a child 

 might inherit all or nearly all of his traits from one parent; such in- 

 heritance he called "alternative" (Fig. 47). 



In other cases the traits of the parents appear to blend in the offspring, 



