“ Fertilization is effected by insects, especially by bees, which are directed in their search by the colour and fragrance of the flowers; but some pollen must also be transported by the wind to the female flowers, especially in arctic species which, in spite of the poverty of insect life, set abundant fruit. The tuft of hairs at the base facilitates rapid dispersion of the seed, early germination of which is rendered desirable owing to its tenuity. Although the limitations of the genus are well marked, and its recognition in consequence easy, it is otherwise with regard to the species. ”

“ Few genera have greater claims to notice from an economic point of view. As timber trees many of the species are valuable from their rapidity of growth and for the production of light durable wood, serviceable for many purposes. Among the best trees of this kind are S. fragilis, the crack willow (fig. 2) , especially the variety known as S. fragilis, var. Russelliana and S. alba, the white or Huntingdon willow. These trees are usually found growing by rivers' banks or in other moist situations, and are generally pollarded for the purpose of securing a crop of straight poles. ”

“ Each male flower consists of a small scale or bract, in the axil of which are usually two, sometimes three, rarely five stamens, and still more rarely a larger number. In addition there is a small glandular disk, which assumes different shapes in different species. The female flowers are equally simple, consisting of a bract, from whose axil arises usually a very short stalk, surmounted by two carpels adherent one to the other for their whole length, except that the upper ends of the styles are separated into two stigmas. ”