208 MANUAL OF HISTOLOGY. 



tissue corpuscles. The relative proportions also of elastic parts may be 

 estimated by the aid of this reagent, and without the microscope ; for a 

 connective-tissue which has a great abundance of the former as compo- 

 nents is rendered but little clearer by this treatment. 



That no solution of the fasciculi takes place is easy of demonstration ; 

 for on carefully washing out a small portion of tissue which has been 

 acted on by the acid, the fibrillae again become visible. 



REMARKS. 1. From the fact that the fibrillse of connective-tissue are so extremely 

 fine, and only appear associated in bundles, it is not strange that at a time not long 

 past their existence as natural structures should have been completely denied. This 

 has happened with Reiehert, in his otherwise so important and stimulating work. 

 According to his view, the ground-mass of parts composed of connective-tissue con- 

 sists of homogeneous, structureless matter, which has a tendency to shrink together, 

 forming folds, which convey to the eye the impression of fibrillse. It has also a 

 tendency to split up in the same direction. Now, although, in former times, the 

 structure of connective-tissue was looked upon to too great an extent as uniform, and 

 the residues of intercellular substance had been frequently overlooked, still every unpre- 

 judiced inquirer into the true state of the case may satisfy himself of the untenableness 

 of Reichert's theory. A portion of living tissue even shows the fibrillse, and examina- 

 tion with the polarisation apparatus teaches their presence also. On transverse sections 

 of tendons, for instance, we may also remark a finely-punctated appearance, which has 

 been regarded by many observers as due to the ends of divided fibrillre. 2. After 

 that Henle had shown that fibres could be isolated by alternate treatment with differ- 

 ent reagents, producing shrinking or swelling, as, for instance, with dilute and con- 

 centrated nitric or hydrochloric acid, Rollett found that steeping in lime-water (or, 

 much more rapidly, baryta) dissolved the cementing substance, so that the fibres could 

 be spread out." According to this observer, connective-tissue resolves itself, on being 

 treated with the reagents in question, either immediately into fibrillee or into bundles, 

 which only divide into the latter on prolonged maceration. Based on these facts, 

 Rollett proposes to distinguish two forms of fibrillation in connective-tissue. For 

 the first of these, tendon affords an example. In the same category he reckons also 

 the bundles of the sclerotica of the aponeuroses, the fibrous ligaments of joints, the 

 dura mater, and the inter-articular ligaments. 



Among the tissues which show the second form of resolution are the cutis, con- 

 junctiva, subcutaneous cellular tissue, submucosa of the intestines, and tunica ad- 

 veiriitia of vessels. In our opinion, the question here only turns upon quantitative 

 differences. 



127. 



By means of the reagents mentioned in the previous section we are 

 enabled also to recognise the elastic elements imbedded in the connec- 

 tive-tissue, which is rendered clear by the former. These are all alike 

 in their power of resisting not only the -action of acids, but also that of 

 potash ley, however much the form in which they appear may vary. 

 The latter is the most important agent for their recognition. 



Elastic fibres are of the commonest occurrence. They are* met with at 

 one time fine, at another of no inconsiderable thickness; sometimes simple, 

 sometimes branched. 



The most delicate elastic fibres (fig. 200, a) were formerly known by 

 the name of nucleus fibres (Gerber and Henle), being erroneously sup- 

 posed to arise from the fusion of fusiform elongated nuclei. They 

 are frequently met with as constituents of connective-tissue in many parts 

 of the body, as, for instance, in that of loose texture lying under the skin. 

 Their diameter may be the same as that of the connective-tissue fibril, but 

 their dark contour and far more tortuous course, their irregularly-twisted, 

 cork-screw-like or hooked appearance, renders their recognition easy. 

 Their peculiar appearance is the result of their elasticity, as well as of the 

 manner in which they have been cut, combined with the swelling up of 



