Hops were first cultivated with a view to obtaining varieties which would furnish abundant and large, well-flavoured flower-heads. The flower-heads are “cones,” consisting of numerous minute flowers, protected by overlapping green-coloured scales or bracts. The cultivated hop was brought to this country in the time of Henry VIII, and the cultivation of hops in hop-gardens and the skilful drying of the flower-heads in large bulk was commenced, and regulated by law. The male or pollen-producing hop-vine is distinct from the female seed-bearing hop-vine; it is the female flower-cone which carries the valuable fragrant and resinous products which the brewer desires. Hops are artificially propagated by root-cuttings, and it is interesting to note that the hop-grower finds that it is not desirable to allow the female flowers to be fertilised, since, although the hops weigh more after the setting of the seed, the valuable extractive substances contained in the flower are diminished, used up in the growth of the seed. Hence, often only one male hop-vine to every 200 female hop-vines is allowed in a hop-garden. [Illustration: FIG. 55.—Early winged female hop-louse, produced viviparously by the first generation of daughters of the “Foundress,” Fig. 58. These winged females migrate from the plum tree, where they were born, to the hop-vines by aid of their wings, and produce viviparously the form drawn in Fig. 57.] [Illustration: FIG. 56.—Male hop-louse, not appearing until late autumn.]