FIFTH LECTURE. 



CONNECTIVE TISSUE. 



TRUE connective tissue, the " cellular tissue " of the older 

 anatomists, is very extensively diffused throughout the body. 

 As a member of the whole tissue group, it also consists of 

 cells and intercellular substance. The latter, on boiling, does 

 not yield the chondrin of cartilage (p. 42), however, but 

 ordinary glue or glutin. The intercellular substance here 

 shows a further metamorphosis in a double direction ; firstly, 

 into the so-called connective tissue bundles and ffbrillae ; and 

 secondly, into the multiform elastic elements. The latter 

 form fibres, reticular fibres, perforated membranes, limiting 

 layers around connective- 

 tissue bundles, and also 

 around spaces which con- 

 tain cells. 



The longest known is the 

 gelatine yielding fibrilla, 

 the constituent which im- 

 mediately attracts the eye. 

 It appears in the form of a 

 very fine, hyaline, un- 

 branched filament, 0.0007 

 mm. in diameter, often 

 very extensible, and at the 

 same time possessing elas- 

 ticity (Fig. 51, to the left). 

 These very readily isolat- 



able fibrillae very commonly unite into sometimes thinner, 

 sometimes thicker bundles (in the figure to the right). Their 

 elasticity very frequently produces an undulated or curly 



