206 MANUAL OF HISTOLOGY. 



We have, in the first place, one species of this tissue which is charac 

 terised by the scanty development of its interstitial matter, while the 

 greater part of it consists of abundant fully-developed connective- tissue 

 corpuscles, either in the form of simple cells or of cellular networks. 

 In this there is no sign of fibrillation, as a rule. The cells may retain 

 their ordinary homogeneous contents, or may become filled with granules 

 of melanin, thus giving rise to the so-called stellate pigment cells. As 

 long as the corpuscles are assembled together without order, the homoge- 

 neous intermediate substance shows no tendency to divide in any definite 

 direction ; but where, in other parts composed of this tissue, the cells are 

 arranged in rows, one after another, the intercellular substance undergoes 

 a change, and becomes scissile in the direction indicated by the position 

 of the cells : it divides into bands and leaves. 



Both arrangements of the cells now lead gradually on to fully-developed 

 connective-tissue, in that the intercellular matter becomes cleft, shreddy, 

 and finally fibrillated. At the same time (and we are here introduced to 

 a new variety of the tissue), the corpuscles either preserve their original 

 cellular character, or are diminished down to their nucleus merely. ISTo 

 less liable to variation is the proportion of these cells and their residue in 

 the different structures formed of connective-tissue. Finally, the elastic 

 elements, whose multifariousness has already been referred to above, dis- 

 play the greatest diversity of form, and in the relative frequency with 

 which they occur. 



The present state of our acquaintance with the nature of connective- 

 tissue, however, leaves much still to be desired. In the first place, we 

 are unaware here and there of the limits of the tissue; and then again 

 the mode of development of parts consisting of it requires a more thorough 

 investigation in many cases than it has yet received. Finally, the nature 

 of the tissue opposes many obstacles to investigation ; for instance, the so- 

 called fibrillse of connective-tissue obscure, as a rule, all the other elements, 

 so that the latter can only be recognised after treatment of the whole with 

 strong chemical reagents. But these give rise to great changes, especially 

 in the cells, and the distorted structures seen by their aid are very differ- 

 ent things from the normal living connective-tissue cells. In regard to 

 the latter our knowledge is still very insufficient. 



REMARKS. In the earlier days of modern histology, connective-tissue was de- 

 scribed as a substance composed of fine transparent fibres, crossing one an other partly, 

 and in part collected together in bundles, but having no farther and especial cellular 

 elementary parts. The latter were first noticed much later. 



126. 



We now turn to the consideration of the elements of typical connective- 

 tissue, and shall, in the first place, describe that part of it which has been 

 longest known and is most characteristic namely, the glutin-yielding 

 fibre. The latter is met with in the form of a very delicate, extensible, 

 and, at the same time, elastic thread, transparent, and having a thickness 

 of about 0-0007 mm., and without branches. 



These primitive fibrillce of connective -tissue (fig. 199) are at times 

 grouped in very varying number, in strands and bundles of extremely dis- 

 similar strength, but may be separated from one another either by simple 

 mechanical dissection or by the action of chemical agents (Rollett), 

 and this with tolerable ease and in considerable length. The elasti- 



