. The microscope and its revelations. his organ, in the insect, or ofthe follicles of the crab, which may beaccomplished with the utmost facility, iswell adapted to give an idea of theessential nature of glandular vertebrated animals the salivaryglands, the pancreas (sweetbreads), andthe mammary glands are well adapted todisplay the follicular structure (fig. 783),nothing more being necessary than to FlG- follicles „ ., •, . of mammary gland, with make sections ot these organs thin enough their secreting cells a a, to be viewed as transparent objects. The containi
. The microscope and its revelations. his organ, in the insect, or ofthe follicles of the crab, which may beaccomplished with the utmost facility, iswell adapted to give an idea of theessential nature of glandular vertebrated animals the salivaryglands, the pancreas (sweetbreads), andthe mammary glands are well adapted todisplay the follicular structure (fig. 783),nothing more being necessary than to FlG- follicles „ ., •, . of mammary gland, with make sections ot these organs thin enough their secreting cells a a, to be viewed as transparent objects. The containing nuclei b of vertebrated animals are made up of elongated tubes, which are straight, and are lined with apavement-epithelium in the inner or medullary portion of thekidney, whilst they are convoluted and filled with a spheroidalepithelium in the outer or cortical. Certain flask-shaped dilata-tions of these tubes include curious little knots of blood-vessels,which are known as the Malpighian bodies of the kidney; these. 1048 VERTEBRATED ANIMALS are well displayed in injected preparations. For such a full andcomplete investigation of the structure of these organs as theanatomist and physiologist require, various methods must be putin practice which this is not the place to detail. It is perfectlyeasy to demonstrate the cellular nature of the substance of theliver by simply scraping a portion of its cut surface, since a numberof its cells will then be detached. The general arrangement of thecells in the lobules may be displayed by means of sections thinenough to be transparent; whilst the arrangement of the blood-vessels can only be shown by means of injections. Fragments ofthe tubules of the kidney, sometimes having the Malpighian cap-sules in connection with them, may also be detached by scraping itscut surface ; but the true relations of these parts can only be shownby thin transparent sections, and by injections of the blood-vesselsand tubuli. The simple follic
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectmicrosc, bookyear1901
