inherited as a Mendelian recessive character. Many other illustrations might be given, but these will, perhaps, suffice to show that Mendelian

Fig. 8. A. Short-haired, Smooth, Pigmented Guinea-pig, illustrating the result of mating two animals like those shown in Figs. 5 and 7 respectively.

Fig. 9. A Short-haired, Smooth, Albino Guinea-pig.

or alternative inheritance is neither a rare nor an exceptional phenomenon, and that it applies to the inheritance not only of characters purely structural, but also to those which are physiological.