CELLULAR TISSUE. 



509 



of its having escaped their notice by being 

 covered and concealed by the protruded blad- 

 der. 



A second class of congenital malformations 

 of the abdominal parietes arises from an excess 

 in the development of certain parts, as a nu- 

 merical increase in the muscles, vessels, or 

 nerves entering into the formation of the abdo- 

 minal parietes, or from the development of a 

 part of a second foetus in connexion with the 

 abdomen. Of the former it is extremely rare 

 to meet with instances among the muscles or 

 vessels of the abdomen ; occasionally we do 

 find an unimportant increase in the number of 

 the costal attachments of one or more of the 

 muscles. As to the latter several cases are 

 recorded in which foetuses exhibited an arm or 

 leg, or even a portion of the trunk of another 

 implanted upon the abdominal wall, or, as is 

 a very rare occurrence, included in it; con- 

 stituting a subdivision of that form of mon- 

 strosity which has been called Diplogenesis. 

 We refer to the article MONSTROSITY for details 

 on this subject. 



Morbid conditions of' the abdominal parietes. 

 These are such as are common to all parts 

 compounded of the same elements as enter into 

 the formation of the abdominal walls, which 

 it would be superfluous to particularise here. 



Congenital malformations of the abdominal 

 cavity. In many acephalous foetuses the ab- 

 dominal cavity is more or less curtailed of its 

 due proportions, the deficiency existing at its 

 superior part. Where the inferior part of the 

 thorax or the pelvis is malformed, the abdo- 

 minal cavity will also be necessarily more or 

 less affected. 



Under this head we may refer to the ano- 

 malies which arise from the congenital mal- 

 position of the viscera, which may extend to 

 the whole contents of the abdomen, or may 

 affect only one or more viscera. Such are the 

 cases of complete transposition of the viscera, 

 where those which in the normal state are on the 

 right side are found upon the left, and vice versa; 

 thus the liver is found on the left, the pylorus 

 on the left, the cardiac extremity of the sto- 

 mach and the spleen on the right, &c. &c. 

 The aorta and vena cava too change places, and 

 the openings in the diaphragm alter their po- 

 sitions along with the parts which respectively 

 pass through them. The same transposition 

 generally extends also to the thoracic viscera. 

 In many of the instances in which this trans- 

 position has been observed, the individuals have 

 lived to the adult period of life without ex- 

 hibiting any symptom indicative of the unusual 

 position of the internal organs.* 



Single viscera are likewise often found trans- 

 posed or in unusual positions, occasioning 

 necessarily corresponding changes in the parts 

 which are connected with them. It is unne- 

 cessary to allude further to them here, as they 



* See Metzger de Translocatione Viscerum,1779 ; 

 also instances in Fuller, Op. Minora, t. iii. ; and 

 several cases of modern date, of which one of the 

 most complete is that published by Bryan in the 

 Transactions of the Irish College of Physicians, 

 vol. iv. 



will be treated of in the articles appropriated 

 to those viscera. 



The morbid conditions of the abdominal 

 cavity are the results of disease affecting its 

 lining membrane or its contained viscera and 

 other parts intimately connected with it. See 

 PERITONEUM and INTESTINAL CANAL. 



For the Bibliography see that of ABDOMEN and 

 INTESTINAL CANAL. 



(R. B. Todd.) 



CELLULAR TISSUE. Tela cdhdosa, 

 textusmucoms, corpus, cribrosum, cellular mem- 

 brane, reticular membrane, filamentous, areolar, 

 laminar tissue, &c. (Fr. tissu celluleux ; Germ. 

 Zellgeweben.) The cellular tissue is the most 

 universally diffused element of organization, 

 and constitutes the basis of every animal body. 

 It consists of a soft, areolated, and elastic sub- 

 stance. A somewhat similar structure also 

 exists in vegetables, constituting their most 

 simple or elementary texture. 



In systematic works the cellular tissue is 

 generally considered as a solid substance ; but 

 as it really exists in the animal body, it is a 

 compound of solid and fluid materials ; for in no 

 part of any animal is the cellular membrane 

 ever entirely devoid of fluid. This union of 

 fluid and solid parts is indeed indispensable to 

 organization, since there is no animal, or even 

 vegetable, in which it may not be demonstrated. 

 In the zoophyte the entire body appears to 

 consist of the cellular tissue, and even in man 

 it enters so largely into the formation of the 

 different organs, pervading equally the most 

 delicate and the most solid parts, that it con- 

 stitutes a species of mould of the whole body 

 and of its individual parts; indeed, if we ex- 

 cept the enamel of the teeth, and, as some 

 authorities contend, also the nails, the hairs, 

 and the epidermis, there is no solid in which it 

 may not be detected. 



Many anatomists have included the adipose 

 tissue under the general -denomination of cel- 

 lular membrane, but as the vesicles of the 

 former are distinct from the cells of the latter, 

 both as regards their formation and the nature 

 of their contents, we rather incline to adopt the 

 views of Malpighi, W. Hunter, Beclard, and 

 others, who contend that the adipose and cellu- 

 lar tissues are distinct and separate structures. 

 (See ADIPOSE TISSUE.) 



Arrangement. The most striking and im- 

 portant fact relative to the cellular tissue is its 

 uninterrupted continuity throughout the whole 

 body, there being no part or region, however 

 insulated it may appear to be, in which this 

 communication may not be demonstrated. 

 Whilst we fully admit this general communica- 

 tion, it is yet necessary to state that the cellular 

 tissue may be appropriately divided into two 

 parts: the first division, called from its dis- 

 position the common or interstitial portion 

 (textus cellularis intermedius vel laxus), is that 

 which occupies the spaces left between the 

 various organs in all parts of the body ; the 

 second division is distinguished by the name 

 of the special cellular membrane (t. cellularis 



