GINANNIA. 



f 290 ] 



GLANDS. 



These are hair- or leaf-like processes (PI. 28. 

 figs. 2g, 15, 19, 31) 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 diifusion 

 by which the respiratory process is effected 

 taking place between the gaseous contents 

 of the tracheae and those of the water. 



GINANNIA, Montague. A genus of 

 Cryptonemiaceae (Florideous Algae), contain- 

 ing one British species, G. furcellata, a rare, 

 pinky-red sea-weed about 2 to 6 inches 

 long, with a dichotomous, terete, membra- 

 naceo-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, Brit. Mar. Alg. p. 148. 

 pi. 19 C; E. Botany, y\. 1881. 



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 ; 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 vesicles 

 of the ovary, and the follicles (Nabothian) of 

 the cervix uteri. 



2. Glands composed of cells reticularly 

 united : the 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 : a, sim- 

 ple, with one or but few lobules, comprising 

 the mucous glands, the sebaceous and the 

 Meibomian follicles ; b, compound, with 

 many lobules, the, lacrymal 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 (Lieberkuhn's), 

 the uterine, sudoriparous and ceruminous 

 glands ; b, compound, consisting of nume- 

 rous 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 trans- 

 udation, are subdivided into : 



1 . Those composed of larger and smaller 

 cells imbedded in a stroma of areolar tissue ; 

 comprising the supra-renal capsules, and the 

 anterior lobules of the pineal gland. 



2. The closed follicles which consist of 

 a basement-membrane, with an epithelial 

 lining and transparent contents, forming the 

 thyroid gland. 



3. The closed follicles, with a capsule of 

 areolar tissue and contents consisting of 

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

 the solitary follicles of the stomach and 

 intestines ; b, the aggregated follicles of the 

 small intestines or Peyer's glands, in animals 

 also those of the stomach and large intes- 

 tines ; c, the glandular follicles of the root 

 of the tongue, and of the pharynx and the 

 tonsils ; d, the lymphatic glands. 



4. Here belongs the spleen, consisting of 

 a cellular parenchyma containing numerous 

 closed follicles. 



5. The thymus gland, in which aggre- 

 gated glandular vesicles open into a common 

 closed canal or wide space. 



The glands are further noticed under their 

 respective heads. 



BIBL. Kolliker, MikrosJc. Anat. and Ge- 

 webelehre, fyc. ; Henle, Ally em. Anat. ; 

 Wagner, Handwb'rterb. d. Phys. ; Todd and 

 Bowman, Phys. Anat. of Man ; Paget, Med. 

 Chir. Rev. 1842. xiv. 



GLANDS, OF PLANTS. The glands of 

 plants are special structures, formed of cel- 

 lular tissue, in which are produced secretions 

 of various kinds, such as oils, resins, &c. 

 They are ordinarily more or less closely con- 

 nected with the epidermal tissues, but not in 

 all cases, the latter instances forming a kind of 

 transition to the receptacles of special secre- 

 tions, turpentine-reservoirs, &c. found in the 

 interior of the stems of many plants. Glands 

 may be conveniently divided into external 

 and internal; the former are sessile, or 

 stalked (when they present the character of 

 glandular hairs, of various forms), while the 

 latter are generally visible externally as trans- 

 parent dots scattered over an organ, such 

 as a leaf, giving it the appearance of having 

 been pricked all over with a pin ; when of 

 more considerable dimensions, and with 

 thicker walls, they produce tuberculation of 

 the surface, as on the rind of the orange, 

 &c. 



External glands. These maybe subdivided 

 into simple and compound. 



