20 Allgemeine Biologie und Entwickelungslehre. 



Harper has studied the problem of prepotency in the coat color inheritance 

 in Equus, using as material the Percheron Stud Book records. He finds the 

 dam prepotent over the sire in the ratio of about 5 to 4. The coat color 

 which has been longest established in the breed, namely gray, is prepotent 

 over black, which has more recently appeared. The author considers the 

 relation of prepotency to age, but reaches no conclusive results. 



In connection with the great activity in the study of inheritance of coat 

 and eye colour in mammals two papers by Pearson ( 2 , 3 ) dealing with the cor- 

 relation existing between these characters and with the changes which they 

 undergo with age in Homo are of importance. Dealing with very large series 

 of statistics he finds that all these correlations are much lower than they have 

 been generally assumed to be. 



In a long and detailed paper Powys deals, from the biometrical standpoint, 

 with the problems of fertility, longevity and reproductive selection in Homo. 

 In the space of a brief abstract it is impossible to summarize the numerous 

 results and conclusions of the work, but its scope may be indicated by quoting 

 the headings of some of the more important sections of the paper which are 

 as follows: "On the correlation between duration of life and number of off- 

 spring; Distribution of fertility ; On the correlation between duration of marriage 

 of females and number of offspring - - at various ages at marriage; Reproductive 

 selection", 



