author's abstract of THia PAPER ISSUED 

 BY THE BIBLIOGRAPHIC SERVICE MARCH 2 



RUBY-EYED DILUTE GRAY, A THIRD ALLELOMORPH 

 IN THE ALBINO SERIES OF THE RAT 



p. W. WHITING AND HELEN DEAN KING 



From the Zoological Laboratory of the University of Pennsylvania and The Wistar 

 Institute of Anatomy and Biology 



INTRODUCTION 



The discovery of a ruby-eyed dilute variety of the Norway rat 

 was announced by Whiting in 1916. As was stated at the meet- 

 ings of the American Society of Naturalists in December, 1916, 

 the factor responsible for this variation has proved to be a third 

 allelomorph in the albino series. 



The dilute rats were taken near the University of Pennsylvania 

 in the spring of 1916. It may be well to give a detailed account 

 of the occurrence of the animals, inasmuch as they were pre- 

 viously unknown. 



Four half-grown dilutes, possibly belonging to the same litter, 

 were seen in a waste-paper house during April. One of these, 

 of unrecognized sex, was reported by a workman as having been 

 caught in a trap. The second, a male, was brought in by the 

 workman; it has been dead for some time. Traps were set and 

 the third, a female, was caught alive on April 7, but died on 

 April 18. One female was found dead in the trap on April 11, 

 along with a wild-type male of the same size which was also dead. 

 Later captures from the same place are as follows : 



On April 14, fourteen full-grown rats — three wild-type males, 

 ten wild-types females, and one dilute female. On April 15, 

 two adults — a wild-type female, and a dilute male. 



On April 20, two adult wild-type females. 



On April 25, one young wild-type female, possibly of the same 

 litter as the young dilutes. 



On May 4, three of the wild type — one young male, one young 



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