Volume 1

General and descriptive anatomy of the domestic animals / by John Gamgee and James Law.

Date:
1861-1862
Catalogue details

Licence: Public Domain Mark

Credit: General and descriptive anatomy of the domestic animals / by John Gamgee and James Law. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

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    4. Open, glandular tubes, with a membrana propria, or a fibr ous coat, and an epithelium. Tubular glands (Fig. 8). The following is Kolliker’s classification of true glands, which applies to the domestic animals as much as to the human body. 1. Glands with short vesicles, which burst occasionally, oi lemain constantly shut. Ovaries, thyroid. 2. Glands whose parenchyma consists of reticulated cells. Liver. 3. Racemose glands, in which collections of roundish or elongated, vesicles are seated upon the ultimate terminations of the excretory ducts. (a) Simple, with one, or few lobules. Mucous glandules, sebaceous glands, meibomian glands. (b) Compound, with numerous lobules. Lacrymal glands, salivary glands, pancreas, prostate, Cowper’s and Bartholine’s glands, mammary glands, lungs. 4. Tubidar glands, whose secerning elements have the form of tubes. (a) Simple, consisting of but one, or some few tubes, terminating in blind extremities. Tubular, gastric, and intestinal glands, uterine glands, sudoriferous and ceruminous glands. (b) Compound, with numerous branches, and, perhaps, reticularly united canals. Testicles, kidneys. We rather incline to the belief that cells, immersed in the fluid office of ceils in secretion. which transudes from the blood-vessels in the recesses of glands, be- come impregnated by materials which undergo change from being- retained -within the cells, and as these are forced onwards they burst, and their contents become characteristic elements of the secretion peculiar to the gland whence it is derived. There are many points to be considered when we compare different glands and their secretions, which may operate in producing the differences observed in the latter.* * The importance of the epithelial elements in glands has been insisted on by Virchow, who says :—“ The really active elements of these organs are essentially of an epithelial nature. One of Eemak’s greatest merits consists in his having shown that in the normal development of the embryo the outer and inner of the well-known three layers of the germinal membrane chiefly produce epithelial structures, from a gradual proliferation of the elements of which glandular structures arise. Other observers, for example, Kolliker, had indeed before him made similar observations, but by Remak was first established the law that the formation of glands in general must be regarded as consequent upon a direct process of proliferation on the part of epithelial structures. Previously large quantities of cytoblastema had been conceived to exist, in which, spontaneously,