GLAND, Gr. cars; Lat. Glandala ; Fr. Glande; Germ. Driise.
An organ whose dlice is to separate from the blood a peculiar substance, almost invariably fluid ; constantly provided with an excretory duct ; formed qf a process of the mucous mem brane or qf the skin, disposed either in the form of a sae or of a ramified canal; which sac or canal in all cases is closed by a blind extremity ; and which, although amply supplied with blood, is never directly continuous with the bloodves sets.* It is absolutely necessary to give this definite explanation of the meaning which is attached to the word gland in the present article, inasmuch as there is no term in anatomy that has been more vaguely, and as it appears to me more incorrectly employed.
It is not necessary to point out the absurdity of applying this word to certain parts of the brain, or to the masses of fat contained in the joints, which were called by the older anato mists glands ; in these instances the fallacy is immediately apparent; but there are other errors which, although less striking, are, I con ceive, no less injurious in their effects. Thus in the glandular system many continental au thorities include not only the liver, kidneys, salivary glands, and other organs, which are universally acknowledged to belong to this class ; but likewise the lymphatic glands, the thyroid, the thymus, the spleen, the supra renal capsules, and the ovaries:I- It is con * The only real exception to this law Is the testicle of fishes, in which no excretory duct seems to exist.
Biehat, after condemning the application of the term to the thyroid, the pineal gland, the lymphatic glands, Am. states, " We ought only to
call those glands, which pour out by one or several ducts, a fluid which these bodies separate from the blood they receive by their vessels." Anat. Gen. torn. ii. p. 598.
ltleckcl, on the contrary, objects to the opinion that an excretory duct is essential to a gland. Ac cording to his definition the glandular system com prises, 1. the mucous glands ; 2. the sebaceous glands ; 3. the liver, the salivary glands, the pan creas, the lachrymal glands, the tonsils, testes, the ovaries, the prostate, Cowper's glands, the kidneys ; 4. the lymphatic glands, the thyroid, the mammary glands, thymus, spleen, supra-renal capsules. Man. d'Anat. tom. i. p. 511.
It is surprising that so admirable a physiologist as Meckel should adopt this opinion.
Professor Willer has also a classification, which scorns to me objectionable ; for he has admitted among the glands the spleen, thyroid, lymphatic glands, &c. It must not, however, he supposed from this arrangement that this profound anatomist considers these particular bodies as real glands. His classification is as follows. ( Ilandbuch der Physiol. des Mensehen, Coblenz, 1834, p. 418.) • A. Ganglia vascalosa, the spleen in the digestive organs-the pra-renal capsules in the genital and uro-poictic viscera-the thymus and o thyroid in the respiratory apparatus IA: glandula choroidalis in the eye-the placenta in the fcctus.
B. G. /gmphatieo-vaseu/osa, the lym e and mesenteric glands.
E `" zrzi } Liver, salivary glands, testis, &c. g c `42