MENTAL CHARACTERS IN MAN 167 



A very similar condition appears in sheep, and also 

 in horses and cattle, as a result of feeding too freely 

 on pampas grass, Poa argentina (Jones and Arnold, 

 191 7). But it is a form of intoxication, and is not 

 inherited. Cole (1920) describes in guinea-pigs a 

 form of congenital palsy which is not exactly like 

 any nervous disorder in man, though it resembles 

 ataxia in pigeons, which Riddle finds is a recessive 

 character with some irregularities in inheritance. 

 Congenital palsy in guinea-pigs runs a brief course, 

 ending in death at an early age. The neurosis 

 appeared in 191 4, and is characterised by clonic 

 spasms,* particularly of the legs, in which the animal 

 lies helpless. It is inherited as a simple Mendelian 

 recessive, heterozygotes being entirely normal. 

 Hurst states that '' feeblemindedness " in pigeons is 

 a recessive. Tumbling in pigeons and *' waltzing " in 

 inice and rats (again recessive) are other examples 

 of inherited nervous disorders in animals. These 

 defects have been shown to be due to defective 

 semicircular canals. 



The inheritance of wildness in rats has been referred 

 to elsewhere. Yerkes (191 3) made a study of wild 

 and tame rats and their Fi and Y^ hybrids. He 

 proved that wildness, savageness, and timidity are 

 inherited, although wildness and timidit}' are very 

 difficult to distinguish. Coburn (1922) has made a 

 study of 1,300 mice, hybrids between wild and tame, 

 in three generations. He made careful psychological 

 tests of his animals, and concludes that the in- 

 heritance of wildness and savageness in mice is 

 Mendelian of the " blending " or multiple factor type, 

 but much more work is needed before the precise 

 manner of inheritance can be stated. He thinks, 

 however, that the two behaviour complexes, wild- 

 ness and savageness, result from several different 



* Spasms in which rigidity and relaxation succeed each other. 



