592 REPORT—1904. 
white; but to the statement that the hybrids have black eyes there was no 
exception in the cases, which exceeded three hundred, that I have bred. The 
hybrids never exhibit waltzing movements, and from the description of their 
coloration it is evident that they are never albinos. When such hybrids are bred 
together they produce a population which, considered from the point of view of its 
colour, falls into three categories: the first is black eye and coloured coat, under 
which heading come half of the population—mice, therefore, which resemble their 
parents; the second is pink eye and coloured coat, and includes a quarter of the 
population, individuals presenting the same features of eye and coat colour as 
those exhibited by the Japanese waltzing mouse; and the third, into which the 
remaining quarter falls, is pink eye and uncoloured coat—that is to say, it is 
albino, If we examine the offspring of hybrids from the point of view of their 
progression, we find that rather less than a quarter waltz, while the rest are 
normal, The waltzing habit in this population is not always associated with the 
same arrangement of eye and coat-colour as that with which it is associated ia the 
pure Japanese waltzer, but may be presented by mice falling into any of the three 
colour categories. To return to the colour question, the albinos, which, it will 
be remembered, form a quarter of the population produced by mating the hybrids, 
breed absolutely true; the pink-eyed mice with coloured coats breed nearly true, 
and the black-eyed individuals with coloured coats produce, when paired together, 
albinos, pink-eyed mice with coloured coats, and black-eyed mice with coloured 
coats, but in what proportions I have not -yet determined. Some of the facts 
which have come to light seem confirmatory of the Mendelian interpretation of 
these phenomena, while others are describable in terms of either Galton’s or 
Pearson’s formula of ancestral inheritance. I do not think, therefore, that I am 
justified in forming an opinion on the question of the relative validity of these two 
interpretations of the facts already observed, and until more data have been col- 
lected I do not propose to do so. . 
3. Experiments on Heredity im Rabbits. By C. C. Hurst, L.L.8, 
An inbred pair of albino Angoras was crossed reciprocally with an inbred pair 
of Belgian hares (F',), and the hybrid progeny were bred with one another for two 
generations (F, and F',). Four characters were under observation, each of which 
was inherited independently of the other. 
1. Angora Coat.—In F, the angora coat was always recessive to the normal 
coat, which was completely dominant. In F, and F, this pair of structural 
characters followed the Mendelian laws of segregation and gametic purity simply 
and without exception. 
2. Albinism.—In F, the albino character was always recessive to the normal 
character, which was dominant, and in F, and F, followed the ordinary 
Mendelian rules. 
3. Coat Colour.—In F, brown x albino gave all with wild grey coats. In 
F, the hybrid greys bred together gave a ratio of 9 grey : 3 black : 4 albino. 
Kixperiments in F, proved that the black factor was not introduced by the 
original brown parent, but by the albino, which, though gametically pure as 
regards simple albinism, was at the same time carrying the distinct factor for 
black coat colour. 
These results in rabbits confirm the important results already gained by 
Cuénot in mice. 
The F, greys proved to be of four kinds—viz., pure grey, grey containing 
black, grey containing albino, and grey containing black and albino, The F, 
blacks were of two kinds—viz., pure black and black containing albino, The 
F’, albinos were of three kinds—viz., albino containing grey, albino containing 
black, and albino containing grey and black. These results are in accordance with 
the Mendelian expectation, which is— 
1G: 2G(B) : 2G(A) : 4G(B)(A): 1B: 2B(A) : 1A(G) : 2A(G)(B) : LA(B) 
—_—__- —— — 
9 grey : 3 black ; 4 albino 
