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with water, so that both sides of the membrane of the pore-canals i* in contact with it, and endosmotic action is set up.

4. The result of' ringing' a Lime-tree, (p. 286).

A Lime which had been * ringed' 10 years before was broken off* at the level of the ring by a storm. The broken surface showed that the wood was diseased, and that the disease had been progressing for some years. The curious point of inquiry is, as to how the diseased tissue, in the plane of the ring, took part in the conveyance of the sap?

5. The result of'ringing' branches of Pines, (p. 286). Although the formation of wood below the rings (but above the

insertion of the branches or their union with the main stem) ceased, yet there was an unusual deposit of resin in the tissues formed previous to the operation.

6. The ' Siebfaser'-tissue as an efficient channel for the descent of formative sap, (p. 287).

Ecferring especially to the age at which this tissue becomes capable of performing its functions. Hartig concludes that it acquires it while yet in the Cambium state, and before it becomes structurally differentiated. By the term 'Siebfasern,' he designates thinwalled, vertically-disposed cells associated with the liber, which evidently serve as a channel for elaborated nutrient fluids. Hartig gave them this name from minute dots which they present at certain points. These dots he fancied indicated actual perforations. They are the Gittersellen of von Mohl, and answer to the vasa propria of the vascular bundles of Monocotyledons. They constitute the most important part of the liber system.

7. On the period of growth in the Boots of Trees, (p. 288).

Dr. Hartig says that the formation of the annual wood-zone ceases during winter, and that its continuing to grow is not normal. H. v. Mohl having stated that, in certain trees, it went on uninterruptedly during the winter, the author concludes that there must have been something exceptional either in the habitat or health of the trees which v. Mohl observed.

8. Upon the alleged dying-off of the root-fibrils (Haarwurzeln, racines cheveluea) (p. 289). Hartig is not acquainted with anything of the sort. The notion, he suggests, may have originated in the change of colour which young fibrils undergo.

9. Upon the membrane closing the canals of the wood-cells of Conifers, (p. 293). The author contends that the lenticular cavities between the wood-cells of Gymnosperms and also of certain Angiosperms, open on one side into one of the wood-cells by which they are enclosed. H. v. Mohl holds that these cavities are closed on both sides, and Schacht, on the other hand, that they are open on both sides. This notice contains the result of microscopic examination of Coniferous wood, into the open cells of the cut surface of a portion of which, coloured particles had been forced by atmospheric pressure. The figures of tbe autbor's preparations certainly confirm his view that the lenticular cavities do open upon one side, and one side only, into tho adjacent cell. Dr. Hartig goes on to describe the mode of origin of the lenticular, intercellular cavities; but this it would not be easy to explain without reproducing his illustrations.

10. Upon the liberation of gas from aerated fluids on their penetration into capillary cavities, (p. 301); and

11. The influence of exhalation upon the rise of the sap, (p. 302); referring especially to the part played by capillary attraction in causing the ascent of the sap, and further unfolding the author's peculiar views in respect to it.

XIII.—Gulliveb's Obseevations ON Kaphides.

Obsebyations On Eapiiides. By George Gulliver, F.E.S. Annals of Natural History. Vols, xi and xii. 1863.

Pbofessob Gulliver proves himself a very diligent crystal-hunter. At first, and probably for recreation, he examined a few plants with a view to ascertain the presence, form, relative abundance, Ac., or the absence of raphides in their tissues. In the January number of the "Annals", he suggests a reference to raphides in systematic diagnoses, and insists upon their great abundance in Onagraceae. In. the July number he attempts to generalize upon them, indicating Natural Orders in which, so far as British species especially are concerned, they abound, and others in which they are absent. In September he proposes to distinguish the 'more or less globular congeries,' of crystals from raphides proper by the special name Sphceraphides. In November he publishes the following passage:— "* * * descriptions of certain Orders can never henceforth be regarded as complete, in any system pretending to be a natural one, without notice of the fact which implies that a fundamental end of the existence of those plants is the production of raphides; for, during their whole healthy lives, such plants may be truly characterized as Nature's laboratories of these curious crystals. And yet, valuable, weighty, and central as this character certainly is, I know not that it has ever yet been recognized by systematic botanists. No other single diagnosis for the Orders in question is so simple, fundamental, and universal as this; and the Orders to which it applies should be designated raphis-bearing or raphidiferoug, and so of the genera or species when all the plants of an Order do not produce raphides "!

Botanists who have spent the better part of their lives in the study of the structure and affinities of plants, cannot refuse a smile when new "fundamental and universal" diagnoses turn up. Professor Gulliver may do useful service to science if he will persevere and very widely extend the field of his observations, as well as inquire into how far the prevalence of raphides in 'raphidiferous' plants may be affected by variety of soil and treatment. His suggestion that the concretionary crystals should be specially distinguished as Sphceraphidea is not a bad one.

M. Eeinsch, in a recent number of a Swiss Natural History Journal (from which we have seen only an extract, without the title), records some observations upon the development of the raphides in the cells of the rhizome of Convallaria. Their development may bo traced by making longitudinal sections of the rhizome backward from the growing-point. Ho makes out that the bundles of raphides originate in 'vacuoles ' in the cells, each vacuole being bounded by a membrane coloured yellow by iodine. Each individual crystal, moreover, is said to be covered with a delicate membrane, likewise coloured yellow by this reagent. As to the origin of the crystals in 'vacuoles,' we confess our incredulity about it. Surely the organic acids of the plant may combine with ordinary bases and crystallize, without going through such a process. With regard to the membrane enclosing the individual crystals, it reminds us of the cellulose (?) film enclosing the crystals, found upon the spicular cells of Welvritschia, the nature of which has been described by Col. Torko (Linn. Proc.—Bot. vii. 100). Wo commend this subject to Professor Gulliver's attention.

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XlV.—LESTTBOtrDOIS OIT Latictfeboits TlSBVTC.

Latex And Laticifebous Tissue. ByT. Lestiboudois. C. RenduB, March, April, July, 1863.

M. Lestibocdois has been trying to clear up the haze which appeared to him to envelop the whole subject of milk-sap in plants; particularly with respect to the part which it fulfils in the vegetable economy, the character of the vessels or receptacles in which it is contained, and the existence or otherwise of a circulation of this fluid.

Excepting in somo trivial details, incidentally given, wo do not observe anything new or noteworthy in his Memoirs, nor do wo aotioe in them any suitable reference to the results of the investigations of two or three skilled German Vegetable Anatomists who have recently occupied themselves with the same subject. M. Lestiboudois is convinced that the 'milk-sap' circulates in entire and uninjured organs, though he does not accept Schultz's explanation of its movement, nor does he offer a substitute. He does not find any basis for the opinion, held by some, that there exists a vascular system in plants, concerned in tho conveyance of nutrient fluids, analogous to that which is characteristic of animals.

XV.—SCHACHT OK THE PniMOEDTAL Tjtbicle. Tjebeb DIE Zeliistoff-fadew IS DEE VOEDEBEN AUHSACKirifO DE8

Ehbbtosackes Von Pediculaeis Stltatica. By H. Schacht. Pringsheim's Jahrb. iii. 339.

On the cellulose threads which are found anastomosing irregularly and forming a plexus in the interior of the blind, sac-like prolongations of the upper daughter-cell of the embryo-sac of Lousewort (Pedicularis sylvatica). Similar formations, Dr. Schacht says, are described by Hofmeister in Veronica triphyllos, and Plantago lanceolata. Dr. Schacht's principal object has been to investigate these formations with a view to see what light they might throw upon the formation of the cell-wall, and its relation to tho protoplasmic contents of cells, especially with reference to the question of tho Primordial Utricle.

At an early stage in the development of the embryo, .numerous active protoplasmic currents may be found traversing the sac-bike prolongations referred to, and by the time the seed is half ripe, a network of threads of cellulose is found corresponding to these currents, and resulting, according to the author, from a gradual change of the protoplasm itself. These cellulose threads continue to increase in thickness so long as the activity of the currents of proto* plasm continues. The formation of these threads from the protoplasm is regarded as analogous to that of the outer layer of the primordial utricle out of the inner granular layer of the Bame, the former passing into the cellulose wall. The various modifications of the secondary deposits of the walls of cells, also the netted striation visible in the wall of liber-cells, are ascribed to the direction of protoplasmic currents upon the inner surface of the wall of the cell. Dr. Schacht considers the formation of cellulose threads in the interior of a cell, resulting from a "gradual change of the protoplasmic streams into threads of cellulose, and a gradual thickening of the latter by the continuance of the protoplasmic motion in the same track," as decisive against the primordial utricle theory of von Mohl, and confirmatory of Pringsheim's notion, with regard to the "TJmwandlung der Hautschicht des Protoplasma in Zellstoff." Pringsheim, it will be remembered, holds that the cell-membrane does not form upon the external face of the primordial utricle, but from a consolidation of the outer layer of the same. Schacht also holds that the cellulose wall is an 'Umwandelungsproduct' of the protoplasm, and that it cannot be regarded in the light of a secretion of the primordial utricle. We do not discover, however, that he brings forward any conclusive evidence in favour of his view, or materially affecting the correctness of von Mohl's arguments in reply to Pringsheim, given in the Botanische Zeitung, 1855, p. 689.

XVI.—Salter's Essay On Monstrous Passion-flowers. On A Sexual Monstrosity, Consisting In The Development

OF POLLENIFEBOUS OVULES, IN THE SPECIES OF Passi

Floba. By S. James A. Salter, M.B., F.E.S., <fcc. Linnean Transactions, xxiv. 143.

We are at a loss to know how to estimate the bearing, both morphological and physiological, of the abnormal structures which Mr.

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