herbage, in others the fruit, seeds, bulbs, tubers, or roots, are fed upon. But vast numbers of insects and some birds (such as humming-birds) draw nourishment from plants mainly from their flowers without destroying or harming them. By their colors, odors, and nectar, blossoms attract insects in great numbers and variety. 2. Nectar, the sweet liquid which most flowers produce, is the real attraction; bright colors and fragrance are merely advertisements. This sweet liquid is often called. honey; but nectar is the proper name for it, as it is not really honey until it is made so by the bee. Some insects also take pollen, either for their own consumption or that of their progeny. That may possibly do the plant some harm. But the nectar they consume is of no use that we know of to flowers, except it be to entice insects. 3. So flowers are evidently useful to insects, and most flowers are feeding-places for them. Where free lunches are provided, some advantage is generally expected from the treat; and we are naturally led to inquire, Why should flowers entice insects to visit them? What advantage are they likely to derive in return for the food they offer? 4. In certain cases the use of insects to flowers is evident enough. When in early spring we see willow-catkins thronged with honey-bees, and notice that their blossoms are of the separated sort,— those of one tree consisting of stamens only, of another tree of pistils only, — and that the bees flying from tree to tree have their bodies well dusted with pollen, we may conclude that the bees are doing useful work in carrying pollen from the stamenbearing flowers that produce it to the pistil-bearing flowers that require it in order to set seed. 5. There are plenty of flowers, however, to which insects could seemingly be of no use. They have stamens and pistils not only close together, but even in contact, — shut up together in some cases, so that some of the pollen cannot fail to be shed upon the stigma. Pea-blossoms are examples of this, having ten anthers closely surrounding one stigma, and inclosed by a pair of the petals. One would say that such blossoms are purposely and effectually arranged to be fertilized without any assistance, and to exclude all interference by insects. Yet they produce nectar, and are visited by bees. 6. Is their nectar provided only for the good of the bee? We might suppose so, until we come to know the remarkable fact that, unless visited by insects, they seldom ripen a pod or set a seed. The showy dicentra, which comes from Japan or Northern China, rarely sets fruit in our gardens in any case; but the wild species of corydalis and fumitory, which have their flowers on the same plan, seed freely enough. Yet when the blossoms are kept covered with fine gauze so as to exclude insects, little or no seed is produced. Evidently, then, for some reason or other, insects sucking their honey are not only useful, but needful even to such blossoms. 7. Nothing is more interesting than to notice how particular flowers, each in its own way, are arranged so as to be helped by the insects that visit them. Iris-flowers, for instance, are visited by bees. These alight upon the outer and recurving divisions of the flower, down the base or which is the only access to the nectar below. When sucking out the nectar with its proboscis, the bee's head is brought down beneath the anther; when raised, it will rub against it and brush out some of the pollen. This, loosely adhering to its hairy surface, is ready to be deposited upon the shelf of stigma above, not when the bee leaves the flower, but when it repeats the action. 8. The remarkable conclusion to which we are brought seems to be this. These flowers are so constructed that the pollen, however near the stigma, is somehow prevented from reaching it of itself, and then honey and other allurements are provided to tempt insects to come and convey the pollen to the stigma. And the various contrivances for hindering the pollen from reaching the stigma directly are excelled only by those for having it done in a roundabout way. So nature appears to place obstacles in the way, and then to overcome the difficulty of her own making by calling in the aid of insects. 9. The solution of this puzzle is simple enough when once hit upon, although it has taken a long time to find it out. It not only makes everything plain as respects all these flowers, but also, as a true discovery should, clears up and explains a great many things besides. The explanation is, that cross-fertilization is aimed at. The pollen was not intended to fertilize that same flower, but to be conveyed to some other flower of the same species. 10. So insects, which had seemed to be needful only when the stamens and pistils are in separate flowers or on separate plants, are quite as needful indeed, are more needful where these organs stand side by side in the same blossom. The reason why crossing is advantageous, and in the long run necessary, is because it has been found that those flowers which are fertilized by stamens growing in other flowers of their kind set more vigorous seed than such as are fertilized by their own stamens. 11. The reciprocity of flower and flower, and of insects and flowers, is something admirable. Insects pay liberal wages for the food which flowers provide for them. This mutual relation is illustrated in a striking-and peculiar manner in the case of the butterflies and moths. Butterflies and moths were once caterpillars, and caterpillars are the especial enemies of plants. Sometimes they kill them; and if they do not quite kill them by eating all their leaves, they often prevent them from bearing fruit. When, however, the caterpillar changes from chrysalis to butterfly or moth, it becomes a winged pollen-bearer, and the zealous friend of many plants. ASA GRAY. Adapted. 20.-CATS, MICE, HUMBLE-BEES, AND CLOVER. cred'i-ble, within belief. ex-ot'ic, foreign. ex-tinct', extinguished. fé'line, of the cat kind. 1. PLANTS and animals, most remote in the scale of nature, are bound together by a web of complex relations. The exotic lobelia fulgens, in certain parts of England, is never visited by insects, and consequently, from its peculiar structure, never can set a seed. 2. Many of our orchidaceous plants absolutely require the visits of moths to remove their pollen-masses and thus to fertilize them. I have, also, reason to believe that humble-bees are indispensable to the fertilization of the heart's-ease, for other bees do not visit this flower. 3. From experiments which I have lately tried I have found that the visits of bees are necessary for the fertilization of some kinds of clover. For instance, twenty heads of Dutch clover yielded 2290 seeds, but twenty other heads protected from bees produced not one. Again, a hundred heads of red clover produced 2700 seeds, but the same number of protected heads produced not a single seed. 4. Humble-bees alone visit red clover, as other bees cannot reach the nectar. Hence I have very little doubt, that if the whole genus of humble-bees became extinct or very rare in England, the heart's-ease and red clover would become very rare, or wholly disappear. The number of humble-bees in any district depends in a great degree on the number of field-mice, which destroy their combs and More than two thirds of them are thus destroyed nests. all over England. 5. Now the number of mice is largely dependent, as every one knows, on the number of cats; and near villages and small towns the nests of humble-bees are more numerous than elsewhere, which I attribute to the number of cats that destroy the mice. Hence it is quite credible. that the presence of a feline animal in large numbers in a district might determine, through the intervention first of mice and then of bees, the frequency of certain flowers in that district. 1. WHY does not every one who can afford it have a geranium in his window or some other flower? It is very cheap; its cheapness is next to nothing, if you raise it from seed, or from a slip; and it is a beauty and a companion. It sweetens the air, rejoices the eye, links you |