ANIMAL ORGANIZATION. 87 



The cellular texture is not only the element, or 

 essential material employed by nature in the con- 

 struction 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 cellular texture is the universal 

 cement employed to bind together all the solid 

 structures. Its properties are admirably adapted 

 to the mechanical purposes which are required in 

 different 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 interposed 

 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 inter- 

 texture closer and more condensed. 



Besides being flexible and extensible, the cellular 



whether cellular, muscular, cartilaginous, or nervous, have their 

 origin from vesicles, which themselves arise from nuclei, by a mode 

 of developement which, in its principle, is similar in all cases ; and 

 that it is only through the modifications which the vesicles subse- 

 quently undergo that the particular tissues are formed and acquire 

 their peculiar properties. Mikroskopische Untersuchungen iiber 

 die Uebereinstimmung in der Struktur und dem Wachsthum der 

 Thiere und Pflanzen, von Dr. Th. Schwann. Berlin, 1839. 



