within a cover of two membranes, an oily moisture mixed with granules the fovilla. Because these corpuscles are so very small is the reason why the theory of fructification is as yet unexplained in many respects; for it requires a microscope magnifying three hundred times to distinguish the granules floating in the fovilla.

The form and the surface of the granules of the pollen varies very much; sometimes they are smooth, sometimes papillary or streaky. The reason why hybridization between many plants similar in their exterior form and shape is difficult we may infer that the form of the pollen is of greater importance than has generally been supposed, and that the form of the pollen must be proportionate to that of the glands and pores of the pistil in order to secure fructification.

At maturity the pollen falls upon the stigma of the pistil, covered with a viscid moisture, whose office it is to retain the pollen, and to cause the bursting of the first exterior membrane of the pollen, by causing it to swell. Then the second membrane containing the fovilla expands more and more, and penetrates, in the form of a tube, between the protuberances through the pores of the pistil into the ovary, where it then effects the fructification of the embryo ovules already formed there.

Fructification is not always so readily accomplished in plants; the stamen and pistil are not always in close or convenient proximity; and here, in the apparently lifeless vegetable world, we are astonished by phenomena which surprise the layman, and almost make the observer believe in a voluntary motion of plants.

Thus, in some plants anthers are remote from the pistil, and the pollen would be uselessly disseminated, but in such cases the anther itself approaches the pistil, strews its pollen upon it, and after fructification withdraws to its old place, as is the case with flax, the potato and tobacco plant. In other plants the anthers are longer than the pistil, and then they bend down to it at the proper period for fructification; sometimes they stand lower than the pistil, and then the pistil bends down to them to receive the pollen. In rye the anthers hang down over the pistil. The coniferous trees are monoecia, i. e., plants having distinct male and female flowers on the same individual. The male flowers on the higher branches drop their abundance of pollen upon the lower flowers, and so the process of fructification goes on from the lowest branch to the top. Other plants bear the male and female organs upon separate individuals, as, for instance, the willows, hop and hemp plants; in their case the wind and insects act as mediators, and often carry the pollen a great distance to the female plant, In all cases of plants the stamen represents the male and the pistil the female sex.

This is a general delineation of the process of fructification, but, as may be seen from the instances mentioned above, it is, in the innumerable varieties of vegetable forms, subject to various modifications, which depend mostly on the shape of the fructifying organs.

Now, when the pistil of a plant has been impregnated with the pollen of the same kind of plants, the seed originating from this impregnation will produce an individual identical to the parent plants.

The knowledge of this law of nature and chance, which latter often has effected great things, induced man to imitate nature in this respect, as has been done with the date-palm in Africa centuries ago, and is still done at present; for as this palm has, like our willow, the sexes on separate trees, the natives often carry the male anthers a distance of many miles to impregnate their female trees artificially.

Here, as in several other cases, it is done merely to secure the fruitfulness of the one or the other individual plant, and it was practiced long since; but the art of producing a new species by crossing two kinds or varieties is of very modern origin.

Hybridization is practiced most extensively in modern horticulture; every body is aware of the innumerable varieties of roses, pelargonias, dahlias, and of most fancy flowers; to enumerate them would be a most difficult task; their number is legion, and it is still increasing every day. All these splendid shades of color have been produced by hybridization. Every reader knows the pansy (viola tricolor) of our gardens, but in the parent plants, (the blue Altai violet), (viola altaica), and the field violet (viola arvensis), from the mutual fructification of which this hybrid originated the splendor of colors, by which their offspring is distinguished and adorns our gardens, may hardly be supposed to exist.

We might name thousands of instances in which hybridizations have been successful in horticulture, and they still increase in number from day to day; for horticulturists are insatiate in their demands upon the beauty of many plants.

Whenever Agriculture went to school to Horticulture, it has always learned something useful, and there is no better school for the progressive husbandman than the garden. Modern agriculture, aiming at a gardenlike culture of the field as its highest ideal, confirms the truth of this prineiple.

Many a practical agriculturist may perhaps reply that hybridization may be well enough as an amusing sport for the florist, but would not do for his serious vocation. Such an objection would not be well founded; for as the florist adds by this means to the splendor of colors in his varieties of plants, and gives a more pleasing form to the structure of the plant and the flower,

so the agriculturist should make the improvement of the plants cultivated by him the object of his endeavors. He will do it, in all probability, in a manner different from that pursued by the florist, who aims merely at a change in the exterior appearance of the plant: he will produce hybrids which will yield a larger amount of useful substances; he will be able to lengthen or shorten, at his option, the period of vegetation of many plants; he may make them as insensible of injurious influences as the form of the seed was; he may establish the excellencies of the one parent of the plant, and entirely remove the defects of another parent, or at least be able to modify them; and all this he may effect much easier and safer by hybridization than by any other means in the culture of plants, such as acclimatization and more careful treatment. That all this is possible can be proved by a multitude of successful hybridizations effected by horticulturists and pomologists, if we had space to enumerate them all. In the animal kingdom we find many hybrids, of which the mule, as a cross between the horse and the ass, is the most common. Besides the accidental crosses between different species of animals, which often produced the most abnormal animal forms, or perhaps better, deformities, the innumerable varieties of the dog furnish striking instances of crossing. The practical husbandman, as breeder of domestic animals, also resorts to crosses between horses, cattle, and sheep, to accomplish his ends. The English-who might be our prototypes in the hybridization of plants-have shown how highly the' races of cattle may be improved by a judicious and consistent system of crossing.

The natural systems of the vegetable kingdom established by Jussieu and De Candolle, give the most reliable information on the affimity of plants. The knowledge of either of these systems is very important to the experimentor, for he may not hope to be successful in his experiments unless he adheres strictly to the rule of selecting only such individuals for crossing as have the nearest resemblance to each other in their organisms. To expect to produce a cross between conifers and deciduous plants in which the characteristics of both are combined would be folly, and it would be still more absurd if one would hope to produce a hybrid by crossing a corn plant upon a potato-having potato bulbs instead of roots, and corn ears at the head.

Hybridization can be successful only between closely related varieties of a family, as they are grouped in the natural system. As an instance, the family of the solanaca may be mentioned here. It has, except in the polar regions, its representatives in every zone, and to it belongs the potato (solanum tuberosum), the most important member of this family. Its more distant relations are the known varieties of henbane (hyoscyamus), tobacco

(nicotiana), Jamestown weed (datura), Spanish pepper (capsicum), and others, each of which possesses its specific kinds and varieties. Thus the potato (solanum tuberosum), has for its next relation the solanum nigrum (common nightshade), and solanum melangana (egg plant), which we know, and these three vegetable forms are named kinds of the same family. The existing varieties of the potato, tobacco, and Guinea (Spanish) pepper, plants which are distinct from each other partly by the form and color of their leaves, or their bloom, partly by the time of maturity, are designated by the term varieties. A correct idea of the division into families, species, kinds, and varieties, is important for hybridization, because experience shows that a cross between varieties is readily accomplished, between individual kinds more difficult, and between distinct species very difficult, if not entirely impossible.

In the family named above, several attempts at hybridization have been made. Thus Klotzsch crossed the solanum tuberosum (potato), with the solanum utile, a kindred variety from Mexico, wherefrom a hybrid resulted, which he baptised the sugar potato, but which, in spite of all commendation, does not promise to become a very valuable acquisition to agriculture, since the luxuriant entangled growth of the vines renders the cultivation of the field difficult, and its flat sweetish taste is unpalatable. As to its value for fodder and technical uses, we are not informed.

Professor John Lindley, in speaking of hybrids between the bean and pea, and the kale and horseradish, mentions also a hybrid between the Jamestown weed and tobacco plant.

Two individuals are necessary for hybridization, namely, a male plant, from which the pollen is taken, and a female plant, upon which the pollen from the male is strewed, and the office of the latter is to bring the seed for the new hybrid to maturity. The two parent plants must be selected with the greatest care and precaution, and the end to be attained by hybridization must be consistently pursued.

Lecoq* has made many experiments with hybridization; has observed that the majority of hybrids produced by crossing always resembled the mother plant more nearly than the male plant, although they possessed the characteristics of the male plant. This view of Lecoq has been adopted by the English writer, Knight, and his countryman, Herbert, even, has found that in general, yet not without exceptions, the male plant exerts more influence upon the foliage, and the female plant upon the flower and seed. According to these principles, a proper selection is difficult to make.

*De la Fecondation Naturelle et Artificielle des Vegetaux et de l'hybridization considërëe dans ses rapports avec l'horticulture, l'agriculture et la sylviculture, contenant les moyens pratiques d'opérer l'hybridization et de creer facilement des varietes nouvelles.-Par HENRI LECOQ, Paris, 1862.

Suppose one possesses a certain kind, A, bearing fruit which is of early maturity, but inferior quality, and wishes to preserve its early maturity and to improve its quality. For this purpose he must select another kind, B, bearing fruit of the desired quality and as nearly as possible of the same early maturity. A should be the mother plant and B the male plant; or, in order to be sure of success, a second simultaneous experiment may be made with two other flowers or samples, in which A is the male plant and B the mother plant. From these crosses, individuals will result which will differ from the parent forms, and show signs of an amalgamation of the characteristics of both. If the desired improvement is not attained in the first generation, then he must select two samples from among these hybrids which approximate nearest the qualities desired, and he must proceed with them in the same way as with their parents, A and B, and so on, in a third or fourth generation, until the desired qualities are obtained. For introductory and instructive experiments, the Indian corn plant may be used; for there are few plants which will hybridize as easily as this does. It will suffice to raise two plants beside each other, but the seed of the earlier blooming and ripening kind must be planted so much later than the later blooming kind, as to make them bloom at the same time. Then, if the two male plants bloom at the same time, they will impregnate each other with their abundant pollen, and in the next generation plants will be produced which will differ from their parents in the time of maturity. But every plant will not be impregnated by strange pollen and its own at the same time as easily as corn. On the contrary, every plant shows a decided preference to being fructified only by its own peculiar pollen; and this fact may be explained, why often an invisible atom of its own pollen suffices for natural impregnation, while for an artificial impregnation a larger amount of strange pollen is required, and this under the most favorable circumstances.

Therefore, in order to insure success in hybridization, the pistil must be protected from the influence of its own as well as of the strange pollen, which is done in various ways-by a timely removal of the anthers from the mother plant; by enveloping the flower, and thus keeping off pollen of its own variety, carried to it by the wind and insects; or by raising the plant at an isolated place, distant from kindred plants. The anthers must be removed at the right time, i. e., before the pollen is ripe and the anther walls are ruptured. All families, and many individual kinds, are different in this respect. In many, the anthers are ruptured before the unfolding of the flower anthemis, or burst during the opening; in others, they come to maturity during the period of blooming.