100 THE MECHANICAL FUNCTIONS. 



construction of all the parts of the animal 

 fabric ; but, in its simplest form, it constitutes 

 the general medium of connexion between 

 adjacent organs, and also between the several 

 parts of the same organ. Like the mortar 

 which unites the stones of a building, the cel- 

 lular texture is the universal cement employed 

 to bind together all the solid structures. Its 

 properties are admirably adapted to the me- 

 chanical purposes which are required in dif- 

 ferent parts of the frame : and these properties 

 are variously modified and adjusted to suit the 

 particular exigencies of the case. When, for 

 instance, different parts require to be moveable 

 upon each other, the cellular substance inter- 

 posed between them has its state of condensation 

 adapted to the degree of motion required. That 

 which connects the muscles, or surrounds the 

 joints, and all other parts concerned in extensive 

 action, has a looser texture, being formed of 

 broad and extensible plates, with few lateral 

 adhesions, and leaving large interstices ; while 

 in the more quiescent organs, the plates of the 

 cellular substance are thin and small, the fibres 

 short and slender, and their intertexture closer 

 and more condensed. 



Besides being flexible and extensible, the cel- 

 lular texture is also highly elastic, a property 

 which is exceedingly advantageous in the con- 

 struction of the frame. Not only the displace- 



