Experimental Hybridizing                    97

The gray (Fj) hybrids were paired with albinos and 537
young produced, of which 261 were albinos and 276 colored —
a close approximation to the expected equality. The colors
were of various kinds, but gray greatly predominated. When
gray {F-^ hybrids were inbred, they produced 119 albinos and
308 colored — a rough approximation to the expectation of
I to 3.

Haacke has pubhshed the results of a large number of crosses
between white mice, colored mice, and Japanese waltzing mice.
Although his experiments were not carried out to test the Men¬
delian law, yet, as the author points out, they closely conform
to this law. Haacke states his general conclusion in a some¬
what involved way, namely, that the possible races of species
equal the number of possible kinds of germ-cells, i.e. equal
a sum that consists of as many factors as a particular species
has independently variable qualities or germinal portions. In
the sum each factor equals the number of all possible modifica¬
tions of its properties.
 

LITERATURE,  CHAPTER VII

Allen, G. M.    The Heredity of Coat Color in Mice.    Proc. of the Amer.

Acad, of Arts and Sci. XL.    1904.
Bateson, W.    The Present State of Knowledge of Color-Heredity in Mice

and Rats.    Proc. Zool. Soc. II.    London.    1903.
Castle, W. E., and Allen, G.    The Heredity of Albinism.    Proc. Amer.

Acad, of Arts and Sci. XXXVIII.    1903.
Cuenot, L.    La loi de Mendel et I'heredite de la pigmentation chez les
souris.    Arch. Zool. Exper. et Gen.    Ser. 3, X.    Notes et Revue.
1902.
La loi de Mendel et I'heredite de la pigmentation chez les souris.

Compt. Rend. CXXXIV.    Paris.    1902.
L'heredite de la pigmentation chez les souris (2™'' note).    Arch. Zool.

Exper. et Gen.    Ser. 4, I.    Notes et Revue.    1903.
L'heredite de la pigmentation chez les souris (3™'' note).    Arch. Zool.

Exper. et Gen.    Ser. 4, II.    Notes et Revue.    1904.
Les Races Pures et leurs Combinaisons chez les souris.    Arch, de
Zool. Exper. et Gen.    Ser. 4, III.    Notes et Revue.    1905.
Darbishire, A. D.    Note on the Results of  crossing   Japanese  Waltz¬
ing Mice with European Albino Races.    Biometrika, II.    1903.
Second Report on the Result of crossing Japanese Watzing Mice with
European Albino Mice.    Biometrika, II.    1903.