340 E. J. ALLEN AND W. E. SEXTON. 
We have therefore mated the few one-sided no-whites which survived 
with normal-eyed animals and with typical no-whites. The details of the 
experiments are as follows :— 
1. Red female, No-white on the Left side, the white reticulation rather 
broken on the Right side, mated with a Red no-white male (Plate VI, 
Fig. 4). 
This female is descended from the B+R-+ A female, VI.A.1.h. (p. 293), 
which was mated with a Red male from Pure Red Stock, and gave a 
brood of 7 young, 3 Black and 4 Red, hatched on May 18, 1916. On 
examining the brood, August 18, 1916, two Black females and three Red 
males were found with 25 young (6 Black and 17 Red), 23 of which were 
normal-eyed, and two, a Red and a Black (see 4), were no-white on the 
Left side. 
The Red one was again examined on reaching maturity and the Left 
eye was found unchanged, still no-white. It was mated with a Red no- 
white male (i.e. one practically normal eye, to three no-white eyes), and 
produced 20 young, all with normal Red eyes (R+N). 
These young were mated together and gave a total of 490, 365 Red- 
eyed, and 125 Red no-whites. In each animal both eyes were of the same 
type. The results therefore are in full agreement with the Mendelian 
theory of the dominance of the white pigment, the numbers required by 
the theory being 367 Red-eyed to 122 Red no-white. 
2. A Black female from Pure Black stock (p. 329) with the Left eye 
no-white, and very little white reticulation in the Right eye, mated 
with a No-white male from the same stock and had 15 young, all with 
normal Black eyes. 
3. An Albino female with the Left eye no-white, i.e. Colourless. Parent- 
age, Albino male carrying Black (A+B) from Brood | of III.B (p. 279) 
and Red female IV.Y (p. 285). The female was mated with an Albino 
male, the eyes of which were very small and the shape of the head ab- 
normal on both sides; 271 young were produced, all with the usual 
Albino eyes and head shape normal. From 3 pairs of these young 
mated within the brood 122 offspring were obtained, 121 being normal 
albinos and 1 being colourless on the left side and normal albino on the 
right, exactly resembling the grandmother. 
4. It may be interesting to add here the account of the young Black 
female referred to in paragraph 1, above, and of the same parentage as 
the Red female described. 
When hatched the Left eye was no-white, and the Right eye had only 
one streak of white in it. It was examined again at maturity and it was 
