Fig. 97. 



GENERAL CONSIDERATIONS ON TEE STRIPED MUSCLES. 179 



either of the helicoid disposition of the fibrillae, or of the fusion of the 

 sarcous elements which compose the latter, according to the admitted opinion 

 as to the structure of the contractile element. 



The muscular fibres are united parallel to each other to form secondary 

 fasciculi, which are surrounded by a con- 

 junctival sheath the perimysium. The 

 secondary fasciculi are laid together to 

 constitute more voluminous fasciculi 

 which, in their turn, form the entire 

 muscle. The conjunctival sheath enve- 

 loping the muscle is named the external 

 perimysium. 



B. TENDONS AND APONEUROSES. The 

 tendons are white, nacreous, round, or 

 flattened cords fixed to the extremities of 

 the long muscles. They are composed 

 of fasciculi of condensed conjunctival 

 tissue, affecting a parallel direction, and 

 united to one another by connective 

 sheaths. 



The aponeuroses belong almost ex- 

 clusively to the wide muscles ; they are 

 formed of several planes of parallel fibres 

 which are not intercrossed in their 

 middle part; at their superficies, how- 

 ever, the fibrous fasciculi are matted toge- 

 ther in a more or less inextricable manner. 



It is very interesting to study the 

 mode of union of the muscular fibres 

 with the tissue of the aponeuroses and 

 tendons, as well as the reciprocal rela- 

 tions of these two parts. 



The muscular fibre may be found passing in the same direction as the 

 tendon, or it may fall upon the latter obliquely. In both cases there is no 

 insensible transition between the muscular fibre and the fasciculus of the 

 fibrous tissue ; on the contrary, the contractile fibre terminates by a rounded 

 extremity, which is buried in a corresponding depression in the tendon or 

 aponeurosis. The union of the muscular with the fibrous tissue is very 

 intimate ; when the muscles are submitted to a degree of traction sufficient to 

 cause a rupture, this never happens at the point of union. 



The tendons commence sometimes by a hollow cone, which receives on 

 its internal face the insertions of its muscular fibres ; and sometimes by a 

 thin point, often divided, which is plunged into the substance of the muscle. 

 It is worthy of remark that a muscle provided with two tendons shows the 

 first-named arrangement at one of its extremities, and the other at its oppo- 

 site extremity ; so that all the fibres which compose the muscle oifer nearly 

 the same length, those which leave the summit of the internal tendon being 

 fixed to the bottom of the hollow cone formed by the second tendon, and so 

 on reciprocally. 



The muscular fibres which are continued by the fibrous fasciculi may be 

 divergent or parallel. In the first case the diaphragm, for example the 

 connective fibres run in the same direction as the muscular fibres. In the 

 second case, several arrangements may be observed : 



TRANSVERSE SECTION OF FROZEN MUSCLE, 

 MAGNIFIED 400 DIAMETERS. 



N, Nerve ; M, Muscular fibre, surrounded 

 by portions of six others. a, Nucleus 

 of the nerve sheath ; 6, Nucleus of the 

 sarcolemma; c, Section of nucleus of 

 terminal plate of nerve ; c?, Transverse 

 section of terminal plate, surrounded 

 by granular material ; e, Transverse 

 section of muscle nuclei ; /, Fine fat 

 drops. The angular dark particles are 

 sections of sarcous elements : the clear 

 intervening spaces represent the fluid 

 isotropal part of the muscle substance. 



