58 ADIPOSE TISSUE. 



same distinct arrangement of an appropriate^ rangement is that each individual grain or 

 organ, but simply masses of adipose, or rather adipose particle is supported by its artery and 

 sebaceous matter, interposed between the at- vein as by a footstalk or peduncle, and those of 

 tached surface of the serous membranes and the same packet are kept together not only by 

 the adjoining or the contained organs. contact, but by the community of ramifications 

 Fat occurs in a third modification in the from the same vessel. These grains are so 

 marrow of bones. The adipose granules, which closely attached that Mascagni, who examined 

 are soft, whitish-yellow, and oleaginous, are them with a good lens, compares them to a 

 here contained in a peculiar membrane-cellular cluster of fish-spawn. Grutzmacher found 

 web, forming numerous vesicles, which may be much the same arrangement in the grains and 

 regarded as an ultra-osseous adipose tissue. It vesicles of the marrow of bones.* 

 is a remarkable proof of the influence of the It has been supposed that the adipose tissue 

 vital principle that during life the substance of receives nervous filaments; and Mascagni con- 

 the bones is never tinged with this animal oil, ceives he has demonstrated its lymphatics. Both 

 but the moment life is extinct, the marrow points, however, are so problematical, that of 

 begins to transude and impart to the bones a neither of these tissues is the distribution known, 

 yellow tint and a greasy aspect. The substance contained in these vesicles is 

 Fat, though chiefly observed to occur in the entirely inorganic. Always solid in the dead 

 bodies of animals, is nevertheless not confined body, it has been represented as being fluid 

 solely to these bodies. Thus not only do va- during life, by Winslow, Haller, Portal, Bichat, 

 rious kinds of oil and consistent oleaginous and most authors on anatomy. The last writer, 

 matter occur in certain vegetables, but sub- indeed, states that under the skin it is more 

 stances similar even to tallow are found in consistent, and that in various living animals 

 some vegetable productions. A sort of he never found it so fluid as is represented, 

 tallow is obtained from the vateria Indica, a The truth is that in the human body, and in 

 forest-tree of the camphor family, indigenous most mammiferous animals during life, the fat 

 in the Indian Archipelago. In a species of is neither fluid nor semifluid. It is simply 

 crotori indigenous in China, namely, the croton soft, yielding, and compressible, with a slight 

 sebiferum of Linnaeus, the stillingia of Mi- degree of transparency, or rather translucence. 

 chaux, or tallow-tree, the seeds are covered This is easily established by observing it during 

 with a quantity of fat, bearing so close a re- incisions through the adipose membrane, either 

 semblance in all its properties to tallow, that it in the human body or in the lower animals, 

 is used by the Chinese in the manufacture of The internal or sebaceous fat, however, espe- 

 candles ; and the fruits of the aleurites triloba, cially that interposed between the fat of the 

 a native of the Sandwich Islands, of the same serous membranes, is much more consistent and 

 natural family with the croton, are the candle- solid. The reason of these differences will be 

 nuts of the inhabitants of these remote regions, understood from what is now to be stated re- 

 It is chiefly in the subcutaneous layer that garding the proximate principles of animal fat. 

 the organization of the adipose membrane has The microscopical and atomical structure of 

 been investigated. The constituent vesicles or fat has recently formed the subject of investi- 

 bags consist of firm, tenacious, ligamentous, gation by M. Raspail.f By placing a portion 

 gray, or whitish-gray coloured substance, mu- of lacerated fat upon a sieve, with an earthen 

 tually united by means of delicate filamentous vessel below it, and directing upon it a stream 

 tissue. These vesicles or sacs receive arterial of water, numerous amylaceous granules are de- 

 and venous branches, the arrangement of which tached and pass through the sieve, and after 

 has been described by various authors, from falling to the bottom of the water afterwards 

 Malpighi, who gave the first accurate account, rise to the surface, in the form of a crystalline 

 to Mascagni, to whom we are, indebted for the powder, as white as snow. When these par- 

 most recent. According to Malpighi,* the tides are collected by scumming, and dried, 

 bloodvessels divide into minute ramifications, they form a starchy powder, though soft and 

 to the extremities of which are attached the somewhat oleaginous to the touch, and which 

 membranous sacs, containing the globules of does not reflect the light in a manner so cry- 

 fat so as to bear some resemblance to the leaves stalline as an amylaceous deposit does, 

 attached to the footstalks of trees. These ve- According to M. Raspail, when examined 

 sicular or saccular arteries are afterwards di- microscopically, these granules present forms 

 vided into more minute vessels, which then and dimensions varying in different animals, 

 form upon the vesicular sacs a delicate vascular in the same animal and even in animals of dif- 

 network. According to Mascagni, who repre- ferent ages, but in all clearly resembling grains 

 sents these vessels in accurate delineations, the offecula. In the human body these particles 

 furrow or space between each packet con- are polyhedral and not susceptible of isolation, 

 tains an artery and vein, which, being subdi- As they are more fluid also than in other 

 vided, penetrates between minute grains oradi- animals, it is necessary to immerse the portion 

 pose particles, of which the packet is composed, subjected to examination in nitric acid or 

 and furnishes each component granule with a liquor potassce, either of which has the effect 

 small artery and vein. The effect of this ar- of consolidating the inclosed or central portion 



* De Omento, Pinguedine, ct Adiposis Ductibus, * De Ossium Medulla, Lips. 1758. 



P. 41. t Repertoire G6nerale d'Anat. 1827. 



