assert that the stem is stretched or protruded, so that the boughs, first situated near the ground are, by the growth and lengthening of the stem, lifted up farther from the earth? this they cannot say : yet they will have great reluctance in admitting the existence of this natural shedding of sprays, for no person who well understands it will ever prune under the idea of improving the shape or increasing the quantity of timber.

It has been stated that it is natural to all trees to have a certain portion of the stem free from branches. The length of the stem clear from branches depends on the situation of the tree. In proportion as the situation is exposed the stem is shorter; but, if it were possible to have a tree grow up to maturity, without ever having its lower boughs either cut off, or destroyed by other trees or bushes, that is, if the ground round about the tree were entirely without any other vegetable whatever, and the situation were open and at the same time the tree protected from any thing that could injure its lower boughs, a tree so situated would, when at maturity, have a portion of its stem free from boughs.

The manner in which the boughs are shed, is much more perfect in some trees than in others. The Oak effects it in the most complete manner. Every one who has at all turned his attention to the growth of the oak, must have observed a number of dead sprays lying under the trees; but the authors of all the works I have read, relating to the management of trees, have omitted to notice these naturally shed sprays.

If the end of one of these sprays be examined, it will be found to resemble the end of the footstalk of a leaf, where it has naturally separated from the spray; it also has an appearance something like the end of a buck's horn, where it has separated from the head of the buck. The shape and appearance of the part that has separated from the tree will convince any one that it is a natural division. The end of the spray is a little convex, and entirely without that jaggedness attending the fracture of living sprays. Now it is after this natural pruning only, that a union takes place between the old and new wood; although many pruners buoy up and encourage themselves with the idea, that the old and new wood unites, where their clumsy operations have been performed: for clumsy indeed, are the operations of the pruner in comparison with those of nature. I may be accused of a want of courtesy; but there is little due to those, who have the assurance to take upon themselves the correction and improvement of a thing, the nature of which they are so ignorant of, as to be unacquainted with the power of trees to discontinue such sprays as are in situations no longer provided with the necessaries for the use of sprays.

If I have succeeded in the attempt to show the necessity of sprays being shed, let not any pruner, blinded with his own sufficiency, imagine this circumstance in favour of pruning. Perhaps it may be said, that it is shown that pruning is a natural operation in the growth of trees, and man, when he performs the work, is assisting nature. But nature does not want this kind of assistance. The only way in which nature can be assisted in the growth of trees, if assistance it must be called, is by improving the situation, and increasing, or bettering the food of the tree. As for instance, the growth of a tree may be encouraged by the removal of surrounding trees; by improving the soil in which it grows; or by protection from any injury it may be liable to. The knife cannot be used on the live part of a tree without inflicting an injury, and lessening the growth. The sprays that drop off of themselves are not shed because they were robbers, but because their situation had become, by the growth of surrounding sprays, unfit, by being made too limited or too dark. Nor do the pruners know which sprays have sufficient room when they cut away so unhesitatingly? If they cut away sprays where there is room for their growth, they, in addition to the injury, by the irreparable blemish inflicted in cutting the wood, retard the growth of the tree. And if they cut away sprays that would of themselves drop off, their labour is useless, and most likely injurious, as the sprays would be removed before there was any necessity. It is worthy of remark, that the young shoots, which seldom fail to show themselves after the pruner's operations, are never to be seen where sprays naturally separate themselves from the tree. All kinds of timber trees practice this natural pruning, but few, that I have observed, in so perfect a manner as the Oak."

Chapter 3rd. On the power of trees to send forth sprays in every suitable situation. Chapter 4th, commences with pruning, wherein he maintains that all pruning necessarily affects and retards the growth of trees. In Chapter 5th. The author maintains that no timber is improved in quality by pruning, but on the contrary, is of less value than that which never was pruned. [See our extract on this subject page 191.] In Chapter 6th. Pruning to improve the shape is treated on and deprecated as useless; and lastly, advice is given on cutting down timber. Although the subject of pruning has been much investigated, both in our Register and various other works, and the majority appear to advocate early and judicious pruning, and although Mr. Ballard condemns pruning altogether, not as being merely useless, but absolutely injurious, yet we recommend the perusal of his little work to all who are interested in Forest Tree culture.

NATURAL HISTORY.

ARTICLE XIII.-ON THE DIFFERENT FORMS OF THE NECTARIUM.

BY F. F. ASHFORD.

SEVERAL of these have been cursorily mentioned as characters of the genus, but though this part of the flower has not hitherto been observed in many genera, yet it may in all probability exist in all, if not a distinct visible part as a gland, or pore, or a set of glands, or pores exuding that viscid sweet juice, so useful secondarily for the nourishment of a great variety of insects, and at the same time, doubtless primarily necessary to the fructuation of the plant itself. For it may be observed in monopetalous tubulose corollas, that though they have no visible nectary, yet there is a nectareous juice, secreted in their tube, which is therefore probably provided with glands for this purpose, too minute to be seen with the naked eye, but which an accurate inspection with glasses, might perhaps detect. Polypetalous flowers, with open calyxes, having no tube or basin for the reception of the nectarious juice, have in general a body destined to prepare and contain it, in order that it may be distributed to the surrounding parts of fructuation as it is wanted. In the compound and umbellate tribe of plants indeed, no nectaries have been remarked, but then it must be remembered, that the whole flower in both of these is so small, that it is no wonder if a part so minute as the nectary frequently is in larger flowers, should escape our observation. In these we may presume, however, that they abound in nectarious juice since we observe that insects are particularly fond of these tribes. No genus in the 12th class has any distinct nectary, but then the calyx is one leaved, and forms a commodious basin, for the reception of the nectarious juice which is frequently discernable in it. The verticilate tube (Class 14 Order 2) also is not mentioned by Linnæus as being furnished with visible nectary, nor is that perhaps necessary here, because the coralla is monopetalous, and the monophylous calyx forms a permanent tube. Many genera of this order have a gland in the bottom of the calyx, surrounding the base of the germ. This is large in the bugle and sufficiently visible in the dead nettle.

No appearance of the nectary is more common than in the form of glands, thus Plukenetia has four glands at the base of the filiments, as in the fifteenth class. Cereis has a style form gland under the germ, Orobanche has a gland at the base of the germ, Cassytha has three glands, Echites five, Hernandia has four or six surrounding the germ, and Grielum has a set of oblong glands round the germ uniting into a little crown, Malpighia has two glands at the bottom and out side of the calyx, in Banisteria, the case is the same, except that one folide of the calyx has no glands, and therefore the whole number is eight instead of ten. Reseda has a gland, arising from the receptacle between the stamens and the upper petal. Croton has five of them fixed to the receptacle, Astronium has five in the disk of the flower, Cucurbita has a single triangular concave gland in the centre of the flower, and in Salix the situation is the same but the form cylindric. Another usual form of the nectary is scales, which are nothing but flatted glands, Vicia has one scale only at the base of the germ, Cusscuta has four at the base of the stamens, but many have five scales as Parnasia, at the base of the filiments in Quassia, between the stamens in Iresine at the base of the germ in Crassula, surrounding the receptacle in Samyda, or at the base of the petals in Ranunculus. Amaryllis has six scales without the base of the filiments.

Not unfrequently does the nectary appear in the shape of valves, which are generally five in number; in Plumbago placed at the bottom of the corolla and inclosing the germ, surrounding the germ in Achryanthus, and covering the capsule in Campanula. Asphodel has six of these valves inserted into the base of the corolla, and forming a complete arch over the germ a filiment springing from each of them.

In Erythronium, there are two callous tubercles at the base of each inner petal; in Laurus, three tubercles round the germ, and two round glands on a short stalk near the base of each filiment of the inner rank, in some species of Iris there are three dots at the base and on the outside of the corolla; in Tamus an oblong dot grows to the inside of each division of the calyx and in Swertia are ten of these dots, two at the base of each division of the corrolla, in Hyacinthus there are three pores at the top of the germ, and in Frittalaria, there is an excavation at the base of each petal, which is considerable, and generally exhibits a large drop of nectareous juice. Mercurialis has two subulate acumens or sharp points, one on each side of the germ, and Vallisneria has cuspis on each petal.

The nectary makes a most beautiful appearance in some species of Iris as a longitudinal villous line upon the petals, in Lilium, it is a pipe or a tubulose line, along the middle of each petal, and Frankenia it is a channel running along the claw.

In some genera the nectary takes the exact form of petals, and was always confounded with them until Linnæus pointed out the differ

ence. This is the case with several plants of the 1st class, and with Lecythis in class thirteen; with all these it is of one petal, in Galanthus it consists of three parallel, notched, obtuse, petal-like leaflets forming a cylinder, about half the length of the corolla. Illicium has several awl shaped folioles of the same length of the petals themselves. Cardiospermum has a four petaled nectary inclosing the germ, Hartogia of five petals. Andrachne has five semi-bifid herbaceous folioles, less than the petals, and placed between them all the Grasses, Rice, and Mays, agree in having a nectary of two oblong minute leaflets. Melianthus has a one leaved nectary within the lowest division of the calyx to which it grows. In Musa, one boat shaped leaf compressed, pointed, and inserted within the bosom of the petal. Ten converging leaflets inclosing the germ form the nectary of Zygophyllum, each leaflet being fixed to the base of each filiment. Dalechampia has a broad nectary composed of many ovate flat plates in several rows. In many genera with tubular corollas, there is a horn or spur at the back of the flower which answers the purpose of a recipient, as in Delphinium, &c. In some species of Anthirrinum the horn is blunted, and becomes rather a bag which is also its shape in Satyrium. In Ophrys, it hangs down from the corolla longer than the petals, and is keeled in the back part; in Serapius, it is of the same length of the petals, of one leaf concave, standing on a pedicle and within the lowest petal; in Arethusa, it is of one leaf, tubulose at the bottom of the ringent corolla, and connate with it, in Cypripedium, is very large and inflated, and in Epidendrum, it is tubulose at the base, turbinate with an oblique bifid mouth. Thus it is observed that all the genera of this tube have singular nectaries, whereas in the third classes (16, 17, 18,) with conjoined filiments, scarcely any are to be found. The numerous genus Carex has an inflated permanent nectary, contracting above and toothed at top, where it gapes, but continues to invest the seed, in Ruscus also it is inflated, and open at top, it is ovate, erect, and of the same size of the calyx:

In many genera, the nectary takes the form of some well known utensil, or other thing; thus in Staphylea it is urceolate or pitcher shaped; in Narcissus, it is infundibiliform, or funnel-shaped; in Epimedium it is cyathiform, or goblet shaped; in Ayenia, it is bell shaped, in Cissampelis, it is well shaped, and in Epidendrum it is turbinate or top shaped narrow at bottom, and spreading out above. The most beautiful of these is the crown shaped; in Diosma, this is placed on the germ; in Olax, it terminates the corolla, but in Passiflora, it is a triple crown, the outer one longest surrounding the style.