138 HEREDITY AND EUGENICS 



side, and the daughters transmitted it better than the 

 sons. Amongst the grandchildren it occurred in four 

 on both sides, in four on one side, and was absent 

 in seven. 



Bronchial asthma and hay fever form a closely 

 associated set of phenomena which are clearly inherited 

 in families, and have their basis in the nervous S3^stem. 

 Hay fever is a slight form of the condition, which may 

 develop asthmatic symptoms under special irritation 

 or lowered bodily vitality, and, as is wtH known, 

 may appear or disappear in an apparently capricious 

 manner at different ages or under different climatic 

 conditions. A considerable study of asthma from 

 the clinical and inheritance point of view has been 

 made by Adkinson (1920). She studied 400 cases, 

 and found a history of asthma in the family in 48 per 

 cent, of the cases. Of the total, 191 were sensitive 

 to proteins, as demonstrated by skin tests, while the re- 

 maining 209 w^ere negative to tests. There was a larger 

 percentage of inherited asthma in the former group. 



The latter t^^pe or '' sensitive asthma " is more 

 like intensified bronchitis. Both types " run in 

 families," and both usually occur in different members 

 of the same familv. Asthma is found to be inherited 

 with equal frequency through either parent. Thirty- 

 eight family histories are presented, and the general 

 conclusion to be drawn from these is that the asth- 

 matic tendency is inherited as a Mendelian recessive. 

 Considering individual cases, " from the father's 

 family 66 patients ma}^ have inherited asthma, 

 39 directly, 8 skipping a generation, i skipping two 

 generations, and 18 collaterally. From the mother's 

 family, 64 patients may have inherited asthma, 

 25 directly, 22 skipping a generation, and 18 col- 

 laterally." It is found that " a nearly equal number 

 of men and women inherit asthma from the father, 

 but twice as many women as men inherit asthma 



