Pyrus acerba.

Pyrus aucuparia.

Pyrus communis.

Pyrus malus.

Pyrus paradisiaca.

Pyrus praecox.

QUAGGA, previous impregnation by.

QUATREFAGES, A. DE, on the burrowing of a bitch to litter. -selection in the silkworm. -development of the wings in the silk-moth. -on varieties of the mulberry. -special raising of eggs of the silk-moth. -on disease of the silkworm. -on monstrosities in insects. -on a change in the breeding season of the Egyptian goose. -fertilisation of the Teredo. -tendency to similarity in the best races. -on his "tourbillon vital." -on the independent existence of the sexual elements.

Quercus cerris.

Quercus robur and pedunculata, hybrids of.