72 THE CONNECTIVE TISSUES, BY A. ROLLETT. 



another, and following accurately, in a longitudinal direction, 

 tlie contour of the cord. In thin transparent membranes, as 

 for example, in the mesentery, or in the arachnoid, these fasci- 

 culi of the connective tissue may be immediately recognised 

 without any preparation. If such longitudinally striated cords 

 be further broken up, we may easily convince ourselves that 

 in accordance with the longitudinal striation they exhibit (fig. 

 2), they may be split into fine smooth fibres, running for con- 

 siderable distances without apparently giving off any branches. 

 The diameter of these fibres is very small, varying from O0006 

 to 0*002 millimeters. These fibres are the fibrillse of the 

 connective tissue ; and when examined by means of the polariz- 

 ing microscope, the fibrils and the fasciculi they form prove to 

 be doubly refractile.* The axis lies in the longitudinal direc- 

 tion of the fibrils, and they behave as positive uniaxial 

 crystals. ~f* They cannot, however, be isolated from the 

 connective tissue by simple mechanical means. We possess, 

 however, in solutions of lime and baryta, fluids which, if they 

 have acted for some time upon connective tissue, loosen the 

 adhesion of the fibres to one another to so great an extent that 

 nothing further is required to obtain the detached fasciculi and 

 even completely isolated fibres for microscopical investigation. 

 The lime-water in which connective tissue, freed as far as pos- 

 sible from extraneous substances (e.g., clean tendon), has under- 

 gone this loosening of its cohesion, contains a substance which 

 can be precipitated from it by means of acetic acid in the form 

 of white granules, which subsequently form flocculi. This re- 

 action still occurs, even if the connective tissue, before being 

 placed in the lime-water, has had all the albuminous substances 

 soluble in water, as far as possible withdrawn from it. The 

 substance taken up by the lime-water, and capable of being 

 again precipitated from it, agrees in its reactions with 



* Erlach, Miiller's Archiv, 1847, p. 322. 



f W. Miiller, Zeitschrift fur Rationelle Medicin, 3 R., Band x., p. 173. 

 See also Valentin, Untersuchung der PJlanzen, und Thiergewebe im polari- 

 sirten JLichte,'}). 265, " Researches on the Tissues of Plants and Animals in 

 Polarised Light ; " and Mattenheimer, Reichertand Du. Bois' Archiv, 1860, 

 p. 354. 



