Dot E. J. ALLEN AND E. W. SEXTON. 
Normal Black Normal Red Normal Cores 
Blacks. No-whites. Reds. No-whites. Albinos. (Al ae No- 
whites). 
Gheory as. b4 1] ih 4 15 5 
Experiment .. 38 11 10 3 14 4 
Since the Plate was made further broods have been obtained from 
this pair and the figures now stand as follows, the total number of young 
being 417 :— 
Normal Black Normal Red Normal Pees 
Blacks. |No-whites. Reds. No-whites. Albinos. ( SE oe 
whites). 
iheony ss 2s <. 176 58 58 20 78 26 
Experiment .. 185 D7 D4 27 75 19 
In addition to the family illustrated in Fig. 1 (Plate VI) a number of 
other matings have been made of blacks carrying red belonging to 
Parent Generation 1 (A+B+R»x RN). Adding together all the figures 
for the young obtained from these matings we have a total of 663 dis- 
tributed as follows :- 
Albino No- 
White (or 
Colourless). 
She or yates i 278 92 92 30 123 41 
Experiment .. 278 93 89 DO 118 3D 
Red with Red. 
Fig. 2 (Plate VI) shows the result of mating together two red offspring 
(Plate III, Fig. 6, 11.D.1.}.2.) of Albino carrying black and red crossed 
with Red No-white. See Parent Generation 1 (A+B+Rx RN). 
Theory requires that out of 16 animals, 12 should show white pigment, 
9 of them being red and 3 albinos, and 4 should show no-white, 3 of them 
being red and 1| colourless. 
Normal Black Normal Red Normal 
Black. No-white. Red. No-white. Albino. 
Fig. 2 shows the first 5 broods with a total of 84 young, and the num- 
bers of each category required by theory for this number are given 
below, with the numbers actually obtamed beneath them. 
Normal Red Normal Colourless (Albino 
Reds. No-whites. Albinos. No-white). 
Theory o: Feesse an. = AT 16 16 5 
Experiment ....... 48 16 16 4 
Since the plate was made further broods have been obtained and the 
total number of young is 141, distributed as follows :— 
Normal Red Normal — Colourless (Albino 
Reds. No whites. Albinos, No-white). 
LINCOM? ee URE ae 79 26 26 9 
Experiment. ....... 79 26 24 12 
In addition to the family illustrated in Fig. 2 (Plate VI) a number of 
other matings have been made of red with red belonging to this genera- 
