Introduction to structural and systematic botany, and vegetable physiology, : being a 5th and revedof the Botanical text-book, illustrated with over thirteen hundred woodcuts . s (Fig. 58, 59), according to their shape. In thisway are formed the various 44. Markings of the Walls of Cells, These, whether in the form ofbands, spiral lines, dots, or apparent pores, all arise from the unequal * From the manner in which the thickening takes place, it would appear thatthe innermost layers must always he the most recent. But M. Trecul has con-vinced himself that the primary cell-membrane sometimes pr
Introduction to structural and systematic botany, and vegetable physiology, : being a 5th and revedof the Botanical text-book, illustrated with over thirteen hundred woodcuts . s (Fig. 58, 59), according to their shape. In thisway are formed the various 44. Markings of the Walls of Cells, These, whether in the form ofbands, spiral lines, dots, or apparent pores, all arise from the unequal * From the manner in which the thickening takes place, it would appear thatthe innermost layers must always he the most recent. But M. Trecul has con-vinced himself that the primary cell-membrane sometimes produces a secondaryone outside of itself, as well as on the inside, so that the original cell-wall isintermediate. And also, that, when the thickening deposit is wholly within theprimary wall, the intermediate layers are occasionally secreted in some way bythe outer or inner ones, and therefore more recent than the inner. Unlikelyas all this seems, M. Trcculs investigations are entitled to great elaborate memoir, upon Secondary Formations in Cells, is published in theAnnates des Sciences Naturelles, 4th scr. Vol. II. 1854. MARKINGS OF THE WALLS OP CELLS. 37. nsfjp distribution of the secondary deposit. They are portions of theAvails which are either thinner or thicker than the rest. Thesemarkings display the greatest variety of forms, many of them ofsurpassing elegance. The principal kinds occur with perfect uni-formity in each species or family, and in definite parts of the plant;so that, in a multitude of cases, the sort of plant may be as certainlyidentified by the minute sculpture of its cells alone, as by more con-spicuous external characters. They are preserved even when thetissue is fossilized, and theexternal form, with every -outward appearance of or-ganization, is thin slices andother contrivances, the hid-den structure is revealedunder the microscope, andthus the true nature of theearths earliest vegetationmay be often satisfactorily
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Keywords: ., bookauthorgra, bookcentury1800, bookdecade1860, booksubjectbotany
