Fig. 9. A dark smooth Guinea-pig.

of rabbits of any desired size within the known limits of variation in size among rabbits, and with any of the conceivable combinations of color factors. Size variation is apparently continuous and its inheritance blending, color variation is discontinuous and its inheritance Mendelian.

Notwithstanding the seemingly radical difference between these two types of inheritance, it is possible that they may, after all, prove to have

Fig. 10. A white rough Guinea-pig.