294 



MANUAL OF HISTOLOGY. 



muscle (a), send off to the fibrilke short transverse branches, which 

 are then broken up into a delicate capillary network 

 (c, d), whose longitudinal tubes pass between the 

 muscular fibres, and communicate with one an- 

 other at long intervals by means of short cross twigs. 

 Thus, a long-meshed capillary network is formed 

 within which the muscle fibre is situated. The 

 proper fleshy substance of the latter receives none 

 of these capillaries. As to the venous vessels, 

 their course corresponds precisely to that of the 

 arterial. 



The nerves met with here will be considered in 

 the next chapter. 



169. 



As is well known, muscles are united very closely 

 with their tendons, and in such a manner that 

 the latter, in their course, appear to be either the 

 immediate prolongation of the muscle fibres, or, the 

 insertion of the latter into the substance of the ten- 

 don takes place at an oblique angle. 



The arrangement of the tissues is, however, essen- 

 tially alike in both cases. Yet for all this it was a 

 long time before conclusive results could be arrived 

 at here, owing to the want of suitable modes of 

 manipulation. 



With a rectilinear insertion of the tendon, there 

 appears to be no sharp boundary between the fleshy 

 substance and that of the connective-tissue, so that 

 a casual observer would be warranted in supposing 

 an immediate transition of one tissue into the other (fig. 291). On the 

 other hand, a completely different appearance is presented, where the 

 insertion of the fleshy fibres is oblique, namely, a sudden termination of 

 the latter, so that simple agglutination of two tissues was supposed to 

 exist here by Koelliker. 



Weismann, on the other hand, succeeded in demonstrating in every 

 case, with the help of strong solutions of potash, the sharp termination 

 of muscle fibres against the tendinous tissue. He showed them to be 

 covered also here with sarcolemma (fig. 292, .&), and to end rounded 

 (a, b), pointed, or obliquely truncated, and so on. They are merely 

 cemented to the tendinous bundle (c, d) >at this point, although most 

 securely. Other macerating fluids may be made use of with similar results, 

 and even immersion in glycerine may produce the desired effect (Biesiadecky 

 and Herzig). 



We are now met by the important question as to the length of the 

 contractile fibres of muscles. 



Do they traverse the latter in their whole extent, or do they terminate 

 before they have done so 1 



It was formerly supposed that each muscle fibre was of the same 

 length as the muscle to which it belonged. More recently, however, the 

 interesting discovery was made by Rollett, that many of the fibres are not 

 obliged to pass through the whole extent of the muscle in order to end in 

 a tendinous bundle, but that the termination of the strongly pointed fibre 



Fig. 290. Capillary net- 

 work of a striped muscle, 

 o, arterial veHsel; 6, 

 venous; c and d, the 

 network of capillaries. 



