CHAPTER 2 

 HEREDITY 



1. General. — 2. Coat color 



Inbreeding brother and sister from the same Utter of Albinos 

 for twenty successive generations (King, 1911-1915, MS) has 

 not been followed by any physical deterioration. 



Studies on heredity in the Norway rat have been concerned 

 mainly with the inheritance of coat color. The gray coat of 

 the wild Norway is dominant in crosses between the wild gray 

 and the Albino. The Albinos in the F 2 generation appear in the 

 proportion of one Albino to three pigmented. In the F 2 and in 

 the later generations pied animals may be had and the color 

 pattern both fixed and modified by selection (Castle, '12, 12 a, 

 and Castle and Phillips, '14). The inheritance of brain weight 

 in the reciprocal crosses Norway X Albino has been studied 

 byHatai (MS '13). 



The references to the literature are grouped into 1) those 

 touching the general problem and 2) those especially applying 

 to coat color. 



heredity: references 



1. General. Castle, '11, '12, '12 a. Castle and Phillips, '14. Crampe, 1883, 

 1884. Darwin, 1883. Hagedoorn, '11, '14. Hatai, '11 a, '12. Lloyd, '08, '09, 

 '11. Pearson, '11. Przibram, '07, '10, '11. Ritzema-Bos, 1894. Yerkes, '13. 



2. Coat color. Bateson, '03. Castle, '14 a, '14 b. Castle and Phillips, '14. 

 Crampe, 1877. Doncaster, '06. Fischer, 1874. Frederic, '07. Haacke, 1895. 

 MacCurdy and Castle, '07. Morgan, '09. Mudge, '08, '08 a, '09. 



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