64 THE CONNECTIVE TISSUES, BY A. ROLLETT. 



which is again dissolved on adding an excess of the acid (mucous 

 tissue, Virchow) * The morphological constituents of the tissue 

 consist of delicate and soft cell structures containing nuclei, 

 from which smooth trabeculse are given off in various direc- 

 tions, that branch and anastomose with one another. Or 

 there may occur in place of the cell plexus a delicate network 

 of smooth non-nucleated trabeculse, which present enlarge- 

 ments at the points where they intercommunicate. A larger 

 or smaller number of amoeboid cells are discoverable in the 

 amorphous substance lying between the fully developed cells. 



The tissue of the jelly-like substance of the umbilical cord 

 described by Wharton, as it appears in the earlier periods of 

 the development of the embryo, is to be reckoned amongst 

 these forms. At a later period, especially in preserved 

 specimens, a not inconsiderable quantity of the original 

 tissue may be found, associated sometimes with fasciculi of 

 fibrils, agreeing with those that, as we shall subsequently see, 

 compose the fibrillse of connective tissue.~f* The substance 

 which occupies the Sinus rhomboidalis of birds is usually 

 regarded as belonging to the mucous or gelatinous form of 

 connective tissue; and a similar material is frequently met 

 with in fishes, especially in the electric and pseud-electric 

 organs ; in the vicinity of the mucous canals of the Sturgeon 

 and Plagiostomata, in various parts of the body in the Carp, 

 Tench, Dace, and Eel, and beneath the sclerotic.^ The vitreous 

 humour of the eye may also be regarded as an example of it. 

 The presence of gelatinous tissue has also been demonstrated 

 in the Invertebrata, Heteropods, Medusae, etc. 



* Wurzburger Verhandlungen, Band ii., p. 160, Cellular Pathologic. 



t Henle, Jahresbericht far 1858, p. 61, et seq. Weismaon, Zeitschrift fur 

 Rationelle Medicin, Bandxi., 3 R., p. 140. Beale, Structure of the Simple 

 Tissues. Koster, Ueber die feinere Structure der Mcnschlich. Nabelschnur, 

 (" On the finer structure of the Umbilical Cord,") Inaug. dissert. Wiirz- 

 burg, 1868, pp. 16 and 17. 



t Ley dig, Muller's Archiv, 1854, p. 316. 



Gegenbaur, Monographic der Pteropoden und Heteropoden. Leipzig, 

 1855. Max Schultze, Muller's Archiv, 1856, p. 314. Leydig, Vergleichende 

 Histologie. Kolliker, Zeitschrift fur wissenschaftliche Zoologie, Band iv., p. 

 363; and Wurzburger Naturw. Zeitschrift, Band v., p. 232, 1864. 



