. The microscope and its revelations. compar-ed, inregard to their grade of or--anisation, with the largeralga?, which consist, likethem, of aggregations of cellsheld togei her by intercellularsubstance, without vessels off FIG. 782.—Section of the branchial cartilage of any kind, and are nourishedtadpole: a, group of four cells, separating bv imbibition through theirfrom each other; b, pair of cells in apposi- , , « rpi tion ;<-,-, nuclei of cartilage-cells; rf, cavity wh°le Surface. There arecontaining tluve cells (the fourth probably many cases, however, inllind)- which t he st met urele
. The microscope and its revelations. compar-ed, inregard to their grade of or--anisation, with the largeralga?, which consist, likethem, of aggregations of cellsheld togei her by intercellularsubstance, without vessels off FIG. 782.—Section of the branchial cartilage of any kind, and are nourishedtadpole: a, group of four cells, separating bv imbibition through theirfrom each other; b, pair of cells in apposi- , , « rpi tion ;<-,-, nuclei of cartilage-cells; rf, cavity wh°le Surface. There arecontaining tluve cells (the fourth probably many cases, however, inllind)- which t he st met ureless inter- cellular substance is replaced by bundles of fibres, sometimes elastic, but more commonly 11011-elastic; such combinations, which are termed ////--cartilages, areinterposed in certain joints, wherein tension as well as pressure hasto be resisted ; as. tor example, between the vertebra1 of the spinalcolumn and the bones of the pelvis. In examining the structureof cartilage nothing more is necessarv than to make verv thin. GLANDS IO47 sections, preferably with the microtome. These sections may bemounted in weak spirit, Goadbys solution, or glycerin-jelly; butin whatever way they are mounted, they undergo a gradual changeby lapse of time, which renders them less fit to display the cha-racteristic features of their structure. Structure of the Glands.—The various secretions of the body (assaliva, bile, urine, etc.) are formed by the instrumentality of organstermed glands; which are, for the most part, constructed on onefundamental type, whatever be the nature of their product. Thesimplest idea of a gland is that which we gain from an examinationof the follicles or little bags imbedded in the wall of the stomach,some of which secrete mucus for the protection of its surface andother gastric juice. These little bags are filled with cells of aspheroidal form, which may be considered as constituting theirepithelial lining; these cells, in the progress of their development
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectmicrosc, bookyear1901
