brave crowd of lambs’ tails.  The elm should flower about the middle of March, and its pink stamens make a pleasant sight.  These plants are called anemophilous—that is, wind-loving, as though grateful to the wind for carrying their

pollen without payment.  I can imagine that the plants employing insects to carry pollen from one to another feel superior to the wind-fertilised clan.  We may fancy the duckweed (speaking of the pine) to say: “Of course, he is very big and of an ancient family, but for that very reason he is primitive in his habits.  I know he boasts that he employs the winds of heaven as marriage priests, but we are served by the animal kingdom in our unions—and that, you must allow, is something to be proud of.” [6]  But duckweeds grow so crowded together that they are probably fertilised, to a great extent, by contact with their neighbours, without aid from the animal kingdom.  We may also imagine the duckweed reproving the pine for his extravagance in the matter of pollen production.  This, however, is necessary, because the pollen being sown broadcast by the wind, it is a matter of chance whether or not a grain reaches the stigma of its own species, and the chance of its doing so is clearly increased by multiplying the number of pollen-grains produced.  Enormous quantities of the precious dust are wasted by this prodigality.  We read of pollen swept from the decks of ships, or coating with a yellow scum lakes hidden among Tyrolean pinewoods.  Pollen is so largely dispersed in the air that it has been supposed to be a cause of hay-fever.

Blackley found, by means of a sticky plate, which

could be exposed and covered again, when raised high in the air on a kite, that pollen is dispersed to considerable altitudes.  Wherever vegetable débris collects, pollen-grains may be found.  Kerner found them, together with wind-borne seeds and scales of butterflies’ wings, sticking to the ice in remote Alpine glaciers.

Another characteristic of wind-borne pollen is dryness or dustiness; the grains are smooth, not sculptured like the pollen meant to be carried by insects; nor are they sticky or oily, as is often the case with entomophilous pollen.  The advantage to the plan is obvious; the grains, from the absence of the burr-like quality, or of any other kind of adhesiveness, do not tend to hold together in clumps, but separate easily from one another, and float all the more easily. [7]

Several adaptations are found to favour the dispersal of the pollen.  Wind-fertilised plants are generally tall; thus in Europe, at least, the commonest representatives of the class are shrubs or trees—witness the fir-trees, yew, juniper, oak, hazel, birch.  And where the plants are lowly—e.g., grasses and sedges, and the plantains—the flowers are more or less raised up on the haulm.  An exception must be made of some water-plants—e.g., the Potamogetons, where the flower-stalk is but slightly raised above the surface.

Wind-fertilised plants have many characteristics which favour the dispersal of the pollen.  The grasses

have long pendent stamens, and versatile anthers, from which the pollen is easily shaken out by the wind.  There are, of course, exceptions to these generalisations.  Such plants as Hippuris and Salicornia have no particular adaptations: the filaments are short, and the plants themselves are not of sufficient height to be able to scatter forth their pollen efficiently by the mere bending of their stems.  The need for exposure to the wind is shown in another way—namely, by the habit of the Cupuliferæ (oak, hazel, etc.), of flowering before the leaves appear; this not only favours the start of the pollen on its flight, but is probably still more useful in increasing its chance of reaching the stigma.

If the pollen is exposed to the wind it will be liable to be wetted and injured.  Catkins—such as those of the walnut or hazel—give some protection to the pollen, since the stamens are covered in by tile-like scales; but where—as in the grasses and plantains—the anthers hang far out of the flowers, the pollen is easily injured.  Some of the cereals protect themselves against injury by means of a remarkably rapid growth of the filaments; thus the anthers remain hidden within the flowers until the last moment, and, under the influence of a warm sunny morning, rapidly protrude themselves.  If the scales of the flower are artificially separated, the growth can be produced by warmth and moisture; Askenasy describes a trick of country children, who put ears of rye in their mouths and thus produce a miraculous growth of stamens.  The growth or rapid turgescence takes place, according to the same

writer, at the pace of one millimetre in three minutes.

The explosive male flowers of the nettle have a somewhat similar meaning.  The young stamen is bent so that the upper end of the anther touches the base of the filament.  On the inner concave side of the stamen are large cells, whose turgescence tends to unfold the filament: I do not know by what means the unfolding is prevented, but whatever the cause may be, it is at last overcome and the stamen uncurls with a jerk, and scatters forth the pollen.  Here, as in the rye, the pollen is protected until the actual moment when it starts on its voyage through the air.

Another of the Nettle tribe, Pilea serpyllifolia—a plant often cultivated in our greenhouses—is also explosive, and its little puffs of smoke-like pollen have gained for it the popular name of the artillery plant.  Its power of explosion must be of value to it as counterbalancing the disadvantage, to a wind-fertilised plant, of such a lowly habit.

The adaptations found in the female organs are chiefly such as increase the surface capable of receiving the pollen, and therefore increase the chance of fertilisation.  A big stigmatic surface is common: not only is the receptive part of the style large, but it usually bears very large stigmatic papillæ, which gives a velvety hoary look to this type of stigma.  In the grasses the three divisions of the stigma are always more or less conspicuous; and reach a climax, in this respect, in the huge beard-like tangle of the maize.

Some of the most interesting cases of wind fertilisation are those in which an isolated instance occurs in a Natural Order otherwise served by insects.  Thus in the Rosaceæ, Poterium sanguisorba is wind fertilised, and has long pendent stamens, and a tufted stigma; while the closely allied Sanguisorba officinalis, although it secretes nectar (and this can only mean that it hopes to attract insects), retains the tufted stigma of its anemophilous relatives.

In the case of the Kerguelen cabbage (Pringlea antiscorbutica), the cause of its degeneration seems to be the want of winged insects on the wind-blown shores on which it grows.  It has acquired some anemophilous characters—e.g., increased stigmatic surface and exserted anthers.  Its flowers are inconspicuous like those of wind-fertilised plants in general, and it seems in fair way to lose its petals altogether—many flowers only retaining a single one.  The entomophilous ancestry of Pringlea is clearly shown by the