GILLS. 



[ 355 ] 



GLANDS. 



from the heart much in the same manner | 

 as the pulmonar} 7 artery ascends from the 

 heart of the higher animals. It may be 

 remarked that the heart of fishes is situated 

 much nearer to the anterior end of the body 

 than in the Mammalia. 



BIBL. Stannius, Vergl. An. ; Lereboul- 

 let, An. Cotnp. de VAppar. Respir. ; Hyrtl, 

 Med. Jahrb. (Ester. Staat. bd. 24 j Leydig, 

 Histol. 382 j Gegenbaur, Vergl. An. 565. 



GILLS OF INSECTS, or branchiae. These 

 are hair- or leaf-like processes (PI, 35. figs. 

 2 y, 15, 19, 21) projecting from the surface 

 of the body, and containing one or more 

 tracheae and their ramifications, which 

 communicate with those of the body gene- 

 rally. Insects furnished with gills or bran- 

 chiae have no occasion to rise to the surface 

 of the water in which they live, the diffusion 

 by which the respiratory process is effected 

 taking place between the gaseous contents 

 of the tracheae and those of the water, 



GINAN'NIA, Montague. A genus of 

 Cryptonerniaceae (Florideous Algae), con- 

 taining one British species, G.furcellata, a 

 rare, pinky-red sea-weed, about 2 to 6 in- 

 ches long, with a dichotomous, terete, mem- 

 branaceo-gelatinous frond, the divisions of 

 which have a kind of fibrous axis. The 

 spores are produced in spherical concep- 

 tacles imbedded just beneath the surface of 

 the frond. 



BIBL. Harvey, Mar. Algce, 148, pi. 19 C j 

 E. Botany, pi. 1881. 



GINGER. This substance finds a place 

 here on account- of its liability to adultera- 

 tion when sold in the form of powder. It 

 consists of the rhizomes of Zingiber offi- 

 cinale (N. 0. Zingiberaceae) . The bulk of 

 the structure consists of parenchymatous 

 cellular tissue with pitted walls, containing 

 scattered starch-granules, and here and 

 there filled with a combined mass of starch- 

 granules and yellow colouring-matter of 

 very distinct character ; besides these, occur 

 the pitted ducts and a small quantity of 

 woody fibre. The starch-grains nearly re- 

 semble those of the species of Curcuma 

 which yield East-India arrowroot. Adul- 

 teration is effected with cheap starches 

 (sago-, wheat-, or potato-flour), which may 

 be detected by the form of the granules ; 

 while MusTABD-husks and CAYENNE pepper 

 are employed to give pungency to the same 

 reduced articles. The characters of these 

 substances are given under their respective 

 heads. 



BIBL. Hassall, Food $c. p. 390. 



GLANDS OF ANIMALS. Glands are 

 organs, the general function of which is to 

 separate from the blood certain compounds 

 destined to perform some special office in 

 the economy. They are divided into true 

 or secernent glands j and vascular glands. 



The secernent glands, the secretions from 

 which escape either by rupture, or through 

 ducts, are thus arranged : 



1. Glands consisting of closed vesicles 

 which dehisce laterally : the Graafian vesi- 

 cles of the ovary, and the follicles (Nabo- 

 thian) of the cervix uteri. 



2. Glands composed of cells reticularly 

 united : the liver. (See LIVER.) 



3. Racemose or aggregated glands, in 

 which aggregations of roundish or elongated 

 glandular vesicles occur at the ends of the 

 excretory ducts. These are either, , sim- 

 ple, with one or but few lobules, comprising 

 the mucous glands, the sebaceous and the 

 Meibomian follicles ; or, b, compound, with 

 many lobules, the lachrymal and salivary 

 glands, the pancreas, the prostate, Cowper's 

 and the mammary glands ; in this category 

 must also be placed the lungs. 



4. Tubular glands, in which the secreting 

 elements have a more or less tubular form. 

 These are either, a, simple, consisting of 

 one or but few caecal tubes including the 

 tubular gastric and intestinal (Lieberkiihn's), 

 the uterine, sudoriparous and ceruminous 

 glands; or, 6, compound, consisting of nu- 

 merous reticular or ramified glandular canals 

 comprising the testis and the kidney. 



The vascular glands, which have no 

 ducts, and the contents of which escape by 

 transudation, are subdivided into 



1. Those composed of large and small 

 cells imbedded in a stroma of connective 

 tissue ; comprising the supra-renal capsules, 

 the anterior lobules of the pineal gland, and 

 the pituitary body. 



2. The closed follicles, consisting of a 

 ba&ement-membrane, an epithelial lining, 

 and transparent contents, forming the thy- 

 roid gland. 



3. The closed follicles, with a capsule of 

 areolar tissue and contents consisting of 

 nuclei, cells, and liquid, to which belong, , 

 the solitary follicles of the stomach and 

 intestines ; 6, the aggregated follicles of the 

 small intestines, or Peyer's glands, in ani- 

 mals also those of the stomach and large 

 intestines j c, the glandular follicles of the 

 root of the tongue, and of the pharynx and 

 the tonsils ; and, d, the lymphatic glands. 



4. Here belongs the spleen, consisting of 



2A2 



