Plate 3.

♂ 103, an evenly marked rat of grade +3. A female rat of this same grade was mated with ♂ 8000 (the wild gray male). Two litters of F₂ grandchildren are shown in 8062-8067, and 8070-8074.

8062 is black hooded, +2; 8064 is gray hooded, +2; 8065 is black, +5; 8066 is gray, +5¼; 8067 is gray, +4½ (notice white feet).

8070 is black hooded, +2; 8071 is gray hooded, +1¾; 8072 is gray, +5; 8073 is black, +5½; 8074 is gray, +5¾.

PLATE 3