The Transactions of the Microscopical Society of London, Volumen 6

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John Van Voorst, 1858

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Página 117 - CARPENTER'S (Dr. WB) Zoology. A Systematic View of the Structure, Habits, Instincts, and Uses of the principal Families of the Animal Kingdom, and of the chief Forms of Fossil Remains. Revised by WS Dallas, FLS Numerous Woodcuts. 2 vols. 6s. each. Mechanical Philosophy. Astronomy, and Horology. A Popular Exposition. 181 Woodcuts. CARPENTER'S Works.— C^tfwW. - Vegetable Physiology and Systematic Botany.
Página 7 - It is not my intention, on the present occasion, to enter into the question of the utility of the allantois at this stage of embryonic life when it is found to be most developed, or to inquire whether it has relation to the nutrition of the embryo, as supposed by Velpeau, or receives the urinary production as well as conducting the foetal vessels to the chorion, according to most embryologists.
Página 69 - Limnsea stagnalis — were consequently introduced, and, by their continued and rapid locomotion and extraordinary voracity, soon removed the cause of interference, and restored the whole to a healthy state, thus perfecting the balance between the animal and vegetable inhabitants, and enabling both to perform their vital functions with health and energy.
Página 186 - To see is one thing, to understand and combine what we see, another ; the eye must be subservient to the mind. Every supposed new species requires to be separated from its allies, and then subjected to a series of careful observations and critical comparisons. To indicate many apparently new species is the work of an hour, to establish only one on a sure foundation is sometimes the labour of months or years. In microscopical natural history as much scrutiny is required to prove a new form to be distinct...
Página 47 - ... and secretion must be driven towards the secreting structure of the gland, which is thus effectually plugged up with a colourless material, and there is no possibility of making out the arrangement of the parts. In such a case it is obviously useless to introduce an injecting fluid, for the greatest force which could be employed would be insufficient to drive the contents through the basement membrane, and the only possible result of the attempt would be rupture of the thin walls of the secreting...
Página 191 - ... (for example, in nepheline and meionite), there are, besides stone- and glass-cavities, many containing water, the relative amount of which indicates that they were formed, under great pressure, at a dull red heat, when both liquid water and melted rock were present. The fluid-cavities in these aqueo-igneous minerals very generally contain minute crystals, as if they had been deposited on cooling from solution in the highly heated water. The minerals in trappean rocks have also such a structure...
Página 47 - ... of an inch in diameter, to their termination in the common duct, and much of the thick layer of epithelium lining their interior was washed out at the same time. The water was removed by placing the liver in cloths with sponges under pressure for twenty-four hours or longer.
Página 68 - ... any part of the leaf which may have received an injury. The materials being thus arranged, all appeared to go on well for a short time, until circumstances occurred which indicated that another and very material agent was required to perfect the adjustment, and which, from my not having thought of it at the time of commencing the experiment, had not been provided against.
Página 191 - The constituent minerals of mica-schist and the associated rocks contain many fluidcavities, indicating that they were metamorphosed by the action of heated water, and not by mere dry heat and partial fusion. The structure of the minerals in erupted lava proves that they were deposited from a mass in the state of igneous fusion, like the crystals in the slags of furnaces ; but, in some of those found in blocks ejected from...
Página 190 - Crystals containing only empty cavities were formed by sublimation, unless the cavities are fluid-cavities that have lost their fluid, or are bubbles of gas given off from a substance which was fused. 6. Crystals containing few cavities were formed slowly, in comparison with those of the same material that contain many. 7. Crystals that contain no cavities were formed very slowly, or by the cooling from fusion of a pure, homogeneous substance.

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