In such a consideration we have to make use not only of the fact just mentioned, but of three important generalizations which serve as it were as implements for the proper estimation of the relationships of any series of organic forms. First of all there is the generalization that the relationships of the various forms of animals (or of plants) to one another is that of the ultimate twigs of a much-branching genealogical tree.
It is also described as a bifurcation of two twigs, mental and bodily creation out of a common root.
Witches-brooms are the tufted bunches of twigs found on silver firs, birches and other trees, and often present resemblances to birds nests or clumps of mistletoe if only seen from a distance.
The small twigs, tied in bundles, are boiled for some time in water with broken biscuit or roasted grain; the resulting decoction is then poured into a cask with molasses or maple sugar and a little yeast, and left to ferment.
Several times during summer the trees ought to be regularly examined, and the young shoots respectively topped or thinned out; those that remain are to be nailed to the wall, or braced in with pieces of slender twigs, and the trees ought occasionally to be washed with the garden engine or thoroughly syringed, especially during very hot summers.