116 



THE ESSENTIALS OF HISTOLOGY 



In the interstices of the muscular tissue there is a little areolar 

 tissue in which run the very numerous blood-capillaries and the 

 lacunar lymphatics. 



FIG. 139. MUSCULAR FIBRES FROM THE 

 HEART, MAGNIFIED, SHOWING THEIR 

 CROSS-STRIDE, DIVISIONS, AND JUNC- 

 TIONS. 



The nuclei and cell-junctions are only repre- 

 sented on the right-hand side of the figure. 



FlG. 140. SlX MUSCULAR FIBRE-CELLS 



FROM THE HEART. (Magnified 425 

 diameters.) 



a, line of junction between two cells ; b, c, 

 branching of cells. 



*/ ' ;H iT' s 



<^i ' ~ << , 



"-^'^1.4 



*H : " . r^ 



. -A^J -'. 



FIG. 141. SECTION OF THE EPICARDIUM OF THE RIGHT AURICLE. 



a, serous epithelium in section ; 6, connective-tissue layer ; c, elastic network ; d, subserous 

 areolar tissue ; e, fat ; /, section of a blood-vessel ; g, a small ganglion ; h, muscular 

 fibres of the myocardium ; i, iutermuscular areolar tissue. 



The myocardium is covered externally by a layer of serous mem- 

 brane the epicardium (cardiac pericardium, fig. 141) composed, like 

 other serous membranes, of connective tissue and elastic fibres, the 



