TEXT-BOOK OF BOTANY (Google eBook)

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Page 311 - ErysiphefB1 form spherical perithecia upon the surface of the substratum which they inhabit, but they remain so small that they can scarcely be seen with the naked eye, whereas the mycelium attains a considerable size. The investment of the fructification is a delicate hollow sphere consisting of pseudo-parenchyma, surrounding the few asci which spring from the carpogonium. The very numerous species of the genus Erysipbe (Mildew) occur upon the surface of the leaves and green stems of Dicotyledons,...
Page 69 - Zinc is dissolved in hydrochloric acid ; the solution is permitted to evaporate in contact with metallic zinc until it attains the thickness of a syrup ; and the syrup is then saturated with iodide of potassium. The iodine is next added, and the solution, if necessary, is diluted with water. Professor Busk gives the following directions for preparing this solution : one ounce of fused chloride of zinc is to be dissolved in about half an ounce of water...
Page 667 - ... and energy is continually being set free at the expense of the protoplasm itself, which must lead to the most complex actions in a substance of so complicated a structure. Every impulse from without, even when imperceptible, must call forth a complicated play of internal movements, of which we are able to perceive only the ultimate effect in an external change of form.
Page 690 - ... again in the evening, this is the result of diminished transpiration with the decrease of temperature and an increase of the moisture in the air in the evening, the activity of the roots continuing, and not of any absorption of aqueous vapor or dew through the leaves. Rain again revives withered leaves not by penetrating the leaves, but by moistening them and thus hindering further transpiration, and conveying water to the roots, which they then conduct to the leaves.
Page 651 - ersatzfasern' (replacing-fibres), because they frequently take the place of the wood-parenchyma. The term 'intermediate' used above refers to the fact that they are intermediate in form between prosenchymatous and parenchymatous cells.] b.
Page 629 - A number of the common bundles (ie those common to the stem and leaves) enter the stem side by side from the broad insertions of the leaves, pass obliquely downwards into it, and then again bend outwards as they descend, approaching gradually the surface of the stem. The common bundle is usually thickest and most perfectly developed at the curved portion which lies deepest in the stem, while the arm which bends upwards into the leaf becomes thinner and simpler upwards, and the descending arm of the...
Page 472 - Generation (Sporophore). The Development of the Embryo. The first division of the oospore (formation of the basal wall) differs from that of Ferns and Rhizocarps, taking place perpendicularly to the axis of the archegonium. According to Hofmeister, each of the two cells first formed is divided in Isoetes in a plane at right angles to that of the first division, the relation of which to the first root, the first leaf, the stem, and the foot of the embryo, requires yet further elucidation1.
Page 95 - ... or of the tissue which afterwards proceeds from them, become, as it were, cut out by lamellae of cork. Since everything which lies outside such a structure dies and dries up, a peripheral layer of dried tissue collects, which is very various in its form and origin. This structure, abundant in Coniferae and in many dicotyledonous trees, is the bark, the most complicated epidermal structure in the vegetable kingdom.
Page 95 - Not unfrequently the formation of cork penetrates much deeper [than the periderm] : lamellae of cork arise deep within the stem as it increases in thickness ; parts of the fundamental tissue and of the fibro-vascular bundles, or of the tissue which afterwards proceeds from them, become, as it were, cut out by lamellae of cork. Since...
Page 667 - ... growing organized body represent a definite amount of work, and the equivalent forces are set free by chemical changes. The essence of organization and life lies in this : that organized structures are capable of a constant internal change ; and that, as long as they are in contact with water and with oxygenated air, only a portion of their forces remains in equilibrium even in their interior, and determines the form or framework of the whole ; while new forces are constantly being set free...

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