On the Hereditary Transmission of Coat Character in Rats. 389 
showed the “ ghost ” of the self-pattern. One of these “ self-ghost ” individuals 
was mated with a Cr 5 (see experiment 37c)* and gave a coloured offspring, 
all of the self-pattern. The young consisted of nineteen “ Irish” 6 individuals, 
obtained in three litters. Since the self-pattern is dominant to the piebald, 
it is clear that the pigmented piebald parent (Cr 5) could not have been 
carrying the self-pattern determiner. The albino parent is therefore the 
only source through which it could have come. And it should be noticed 
that one of its G-Ps. (experiment 74), and three of its G-G-Ps. (experi- 
ments 71 and 664A) had the self-pattern coat. 
Now, on the basis of gametic purity and segregation, it is expected that 
one-half of the 15 offspring in experiment 194 of which the albino parent 
described above was one will carry the self-pattern determiner. By an 
ocular demonstration, corroborated by a subsequent breeding test, the expecta- 
tion is thus shown to be fulfilled. 
(2) Cr 4xCr 5 = Albino x Prebald Black-White. 
(a) Heterozygous Prebald x Albino. 
Experiments 29, 30, 31, 33, 34, 36, 87 and 37a. 
The expectation in this cross is 1 Cr4:1 Cr 5. The result is 44 Cr 4455 
Cr5. The high proportion of the Cr 5 type is due to mating No. 30 (p. 391). 
If this is eliminated; the figures are 32 Cr 4+33 Cr 5. The disturbance 
of the proportions is due to the last two litters of this mating. They are:— 
Ist litter = 3 Cr 444 Cr 5 
meh 6 fee EA, 
210 Clear Ne-yo) a 
AECL De =O.) eke esthO! <5 
In experiment 34, one of the four albino offspring showed the piebald 
“ chost ” pattern in its coat. 
(b) Homozygous Prebald x Cr 4. 
Hapervment 32. ° 
The expectation is that all the offspring shall be Cr 5. The result is 
14 Cr 5. 
(c) Prebald x Cr 4 of more Complex Constitution. 
Experiments 35, 378, and 37c. 
In these crosses the result will depend upon the nature of the albino 
parent. If it be of cgBSsP constitution and the Cr 5 parent carries c recessive, 
* See also Pedigree Chart 1, in first paper. 
2H 2 
