CHAPTER II. 

 THE CONNECTIVE TISSUES. 



9. THE most widely distributed texture in the body is that 

 which is termed connective tissue. It is the substance which 

 connects the integument everywhere with the deeper struc- 

 tures, and it makes partitions between these structures and 

 between the elements of which they are composed. Thus 

 every muscle has a filmy sheath, which, when separated, is 

 seen to consist of a felted white substance, sending in pro- 

 cesses into the muscle, dividing its substance into bundles, 

 and these into still smaller bundles by finer investments. 

 The same substance separates the bundles of every nerve, 

 and surrounds the blood-vessels; it is found in great quan- 

 tity among fat and beneath the integument, and it forms in 

 fact a continuous web in which all the structures throughout 

 the body are imbedded. 



This tissue, looked at with the microscope, exhibits two 

 elements : first, a matrix, which, in those places where it is 

 most closely mixed up with other textures, is often homo- 

 geneous or nearly so, but which, in the denser specimens 

 obtained from distinct masses, assumes the appearance of 

 extremely fine fibres of indefinite length, disposed in irre- 

 gular felted fashion, leaving spaces, from which the tissue 

 gets the name areolar ; secondly, nucleated corpuscles, 

 called in this instance connective-tissue-corpuscles. 



A drop of dilute acetic acid added to the specimen under 

 the microscope, causes the fibres of the matrix to 'swell up and 

 become indistinct, bringing the nuclei of the corpuscles clearly 

 into view, and also a variable admixture of isolated fibres 

 on which the acid has no effect. The fibres on which acetic 

 acid has no action are called elastic fibres, and will be further 

 referred to ; those which are swollen up by the acid are called 



