aie By Oh, ZIbDID INE, 
Mated together the albinos give all albino offspring, whatever their 
constitution, since neither parent contains the colour factor, which we 
have indicated by great ©, which enables the colour to appear. 
AMMARUS ALBINO GX © ateino EYE COLOU 
OlOlOlOLOlOlLOLOlOlOlelelele) NOC 
QO 
~~ 
ALBINO CARRYING. BLACK (x X 4¢ RED,NO WHITE 
| Jt 
ALBINO CARRYING RED (Xx <> PURE RED 
4 
Bese se 4B 4eRsdbsdB share sre sn snansnsnar 
sa i a A a a 
ALBINO 
CARRYINC BLACK AND RED 
Ox ‘ PURE RED 
2esabadb ser snsnsnsnsanad 
NULL YUE SA SUAS Til JET as VIS FC Bes SC 
DIAGRAM 9. 
(Signs as in Diagram 7.) 
Mated with pure red, albinos give three kinds of broods : 
(1) All black-eyed young. In this case the albino contains the factor 
for pure black, which is dominant to red. 
(2) All red-eyed young. In this case the albino contains pure red. 
(3) Black-eyed and red-eyed young in equal numbers. The albino is 
then hybrid as regards colour, containing factors for both 
black and red. 
There is still another sport or mutation which has occurred in the eye 
of Gammarus. This is the entire absence of the chalk-white pigment 
which lies near the surface between the ommatidia. (Plate VII, Fig. 5, 
of preceding paper.) These we call “ no-white ” eyes. 
Animals with eyes like this may be either black-eyed or red-eyed, and 
the black-eyed ones may be either pure black or hybrid black containing 
red. By cross-breeding we have obtained all three kinds. 
The character “ no-white ” is transmitted to the offspring in strict 
accordance with Mendel’s law, the presence of white pigment being 
dominant and its absence recessive. If an animal therefore which 
possesses the white pigment is mated with one which does not possess it 
the offspring in the first gencration all have the white pigment—their eyes 
are quite normal. If males and females of this first generation are mated 
together, in their offspring—in the grandchildren of the original pair— 
‘ no-whites ” reappear. 
