248 



THE HEART, BY F. SCHWEIGGER-SEIDEL. 



have a length of about 0'014, and a breadth of about O'OOT mil- 

 limeters ; whilst the muscle cells themselves measure, on the 

 average, 0'050 to 0*070 millimeters in length, and 0'015 to 

 0'023 millimeters in breadth. The cellular elements are, for the 

 most part, united to one another in the longitudinal direction, 

 but in various parts they send off short lateral processes, which 

 coalesce with those of neighbouring cells, and in this way form 

 the anastomoses that occur between the longitudinal fibres. The 

 cells are only placed in direct apposition to one another, in a 

 transverse direction, in those parts where the stronger muscular 



Fig. 41. 



Fig. 41. Anastomosing muscular fibre of the heart, seen in a longi- 

 tudinal section. On the right, the limits of the separate cells "with 

 their nuclei are exhibited somewhat diagrammatically. 



trabeculse are formed. If, however, we consider the abundance of 

 capillaries which, together with nerves and connective tissue, tra- 

 verse the muscle substance in Mammals, we shall arrive at the 

 conviction that it is impossible for any material to be of a more 

 compact nature. Sections in various directions establish this 

 most satisfactorily, and transverse sections, made from well-hard- 

 ened hearts (fig. 39), are admirably adapted for the purpose. But 

 in fine longitudinal sections, numerous larger or smaller fissures, 

 arranged in a stellate manner, may also be seen, and so fine 

 that they have been described by some observers as fissures or 



