MENDELIAN CHARACTERS 215 



pigeons, fowls, cats, and so on. In butterflies and 

 other insects, and even in snails, similar phenomena 

 have been described. The study of the larger domestic 

 animals awaits for the present the proper endowment 

 of these researches. When this takes place, the 

 inheritance of far more important characters than 

 colour will be adequately studied to the great profit of 

 all who are concerned in the breeding industry. Hurst 

 has already shown from an examination of the stud- 

 book that the bay and brown colours of thoroughbred 

 horses are Mendelian dominants to chestnut.* 



Other characters of the most diverse kinds are also 

 similarly inherited. We have already referred to 

 structural characters in maize and in peas. Stature 

 is a character which is definitely inherited in many 

 plants. Among more subtle characters a similar mode 

 of transmission has been found in the case of differences 

 in chemical composition, and in that of immunity 

 from and susceptibility to the attacks of certain 

 diseases. The thrum-eyed condition of the primrose 

 has been shown by Bateson and Gregory to be a 

 Mendelian dominant to the pin-eyed condition, so that 

 we have here a partial solution of a problem which is 

 rendered specially interesting from the fact that it 

 baffled Darwin. 



A study of numerous pedigrees has enabled Bateson 

 and others to show that in the case of the human race 

 certain congenital diseases are simply transmitted from 

 parent to offspring in accordance with Mendel's law. 



* [Other colour characters have now been shown to have 

 Mendelian inheritance in hoises, cattle., sheep, etc.] 



