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On Some Features in the Hereditary Transmission of the Albino 
Character and the Black Piebald Coat in Rats.—Paper II. 
By GEORGE PERcIVAL MupceE, A.R.C.Sc. Lond., Lecturer on Biology at the 
London Hospital Medical College (University of London) and at the 
London School of Medicine for Women (University of London), 
(Communicated by Professor A. D. Waller, F.R.S. Received J anuary 14,— 
| Read May 21, 1908.) 
This paper contains a further record of experiments which were begun at 
the same time as those recorded in my first paper.* The method of 
interpreting results in the present paper is the same as that used in the 
first one, and is based upon the same working hypothesis, 7.¢., Bateson 
and Punnett’s “ Presence and Absence” hypothesis and Cuénot’s theory of 
colour. The cost of these experiments has been defrayed by a grant from 
the Government Grant Committee of the Royal Society. 
THE EXPERIMENTAL MATINGS. 
(1) (a) Cr 4x Cr 4= Albino x Albino. 
Twenty pairs of albinoes were mated. There was a total offspring of 174 
individuals, all albinoces. Some of these albinoes had a near albino ancestry, 
while others had a pigmented one. The details of the ancestry may be seen 
upon reference to the Table of Ancestry, pp. 390—391. 
(b) “ Ghost” or Zygotic Patterns im Albinoes, 
I have already, in the first paper, given an account of the “ghost” pattern 
as shown in the offspring of one mating (experiment 74). I have now to 
describe a second case. In experiment 19A there was a total offspring of 15, 
in two litters of six and nine individuals. The first litter was at a much 
earlier date than the second, and I did not pay any particular attention to 
the appearance of the coat in the individuals of this litter. By the time the 
second litter was born, I had discovered the existence of the “ ghost ” pattern 
in albinoes. It is possible, therefore, that the first litter showed it, but since 
it is only a transitory matter of a few weeks, it will be unobserved unless 
looked for at the particular period at which it appears. Of the nine albinoes 
born in the second litter, two died quite young, and the remaining seven all 
* “On Some Features in the Hereditary Transmission of the Self-black and the “ Irish” 
Coat Character in Rats.—Part I,” ‘ Roy. Soc. Proc.,’ B, vol. 80, 1908. 
