A Text-book of Botany, Part 1

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Macmillan, 1898 - 632 pàgines
 

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Pàgina 46 - A highly organized plant which begins its development with the simplest stages and gradually advances to a higher state of differentiation repeats in its ontogeny its phylogenetic development " ; and further on, " From the fossil remains of former geological periods it is safe to conclude that such Conifers as Thuja, Biota, and the various Jumpers that now have scalelike compressed leaves have been derived from Conifers with needle-shaped leaves. This conclusion is further confirmed by...
Pàgina 125 - ... with similar functions, but with the structure and thickenings of vessels; (ft), fibre tracheids with small lumina and pointed ends, having only small, obliquely elongated bordered pits, and, in extreme cases, exercising merely mechanical functions; (g...
Pàgina 194 - ... organic remains contribute in the most efficacious manner to the fertility of the soil. Besides, we are far from being able to affirm that the carbon of plants is derived from the carbonic acid of the atmosphere. Doubtless this acid is its principal source ; but it is possible that certain elements of carburetted dungs may be directly assimilated. The writers who have treated of manures, have generally formed them into two grand classes : 1st. Manures of organic origin, in which are again found...
Pàgina 285 - Bee. 2, older flower, with connective withdrawn and elongated style. 4, the staminal apparatus at rest, with connective enclosed within the upper lip. 3, the same when disturbed by the entrance of the proboscis of the Bee in the direction of the arrow. / = filament. c -connective, s-the obstructing half of the anther, which produces no pollen.
Pàgina 74 - ... sap of a number of deeply colored parts of plants in a crystalline or amorphous form. Blood-colored leaves, such as those of the copper beech, owe their characteristic appearance to the united presence of green chlorophyll and anthocyanin. The different colors of flowers are due to the varying color of the cell sap, to the different distribution of the cells containing the colored cell sap, and also to the combinations of dissolved coloring matter with the yellow, orange, and red chromoplasts...
Pàgina 371 - The Fungus derives its nourishment saprophytically from the organic matter produced by the assimilating Alga, without at the same time behaving as a parasite and injuriously interfering with its vegetative activity.
Pàgina 5 - The second and much larger part is divided into a general and a special part. In the general part...
Pàgina 47 - Junipers that now have scalelike compressed leaves have been derived from Conifers with needle-shaped leaves. This conclusion is further confirmed by the fact that on the young plants of the scaly Conifers typical needle-shaped leaves are at first developed. The modified leaf-form does not make its appearance until the young plant has attained a certain age, while in some Junipers needle-shaped leaves are retained throughout their whole existence.
Pàgina 75 - The different colors of flowers are due to the varying color of the cell-sap, to the different distribution of the cells containing the colored cell-sap, and also to the combinations of dissolved coloring matter with the yellow, orange, and red chromoplasts and the green chloroplasts. There is occasionally found in the cell-sap a yellow coloring matter known as xanthein; it is nearly related to xanthophyll, but soluble in water.
Pàgina 91 - Heating, even to redness, does not destroy the structure of such silicified epidermal cells. Deposits of wax are also present in the cutinised layers of the epidermis, and consequently water will flow off the epidermis without wetting it. The wax is sometimes spread over the surface of the cuticle as a wax covering. This is the case in most fruits, where, as is so noticeable on plums, it forms the so-called bloom. The wax coverings may consist of grains, small rods (Fig.

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