SICHEL, J., on the deafness of white cats with blue eyes.

SIDNEY, S., on the pedigrees of pigs. -on cross-reversion in pigs. -period of gestation in the pig. -production of breeds of pigs by intercrossing. -fertility of the pig. -effects of interbreeding on pigs. -on the colours of pigs.

SIEBOLD, on the sweet potato.

SIEBOLD, CARL VON, on parthenogenesis.

Silene, contabescence in.

SILK FOWLS.

SILK-MOTH, Arrindy.
-Tarroo.

SILK-MOTHS. -domesticated, species of. -history of. -causes of modification in. -differences presented by. -crossing of. -disease in. -effects of disuse of parts in. -selection practised with. -variation of. -parthenogenesis in.

SILKWORMS, variations of. -yielding white cocoons, less liable to disease.

SILVER-GREY rabbit.