MUSCLES. 



367 



Fig. 151. 



Fig. 152. 



Fragment of Muscular 

 Fibre from macerated heart 

 of Ox, showing formation 

 of striag by aggregation of 

 beaded fibrillae. (Bowman.) 



Portion of Human Muscular Fibre, separating into disks, by 

 cleavage in direction of transverse striae. (Bowman.) 



fibrillge are the ultimate elements of the fibre; these segments being 

 connected longitudinally, so as to constitute the fibrillae, the distinct- 

 ness of which is marked, even in the complete fibre, by longitudinal 

 striae ; whilst they also adhere laterally, so as to form disks, the par- 

 tial separation of which gives origin to the transverse striae. 



The views of histologists on 



the whole of this subject have Fig. 153. 



until recently been sufficiently 

 discrepant. Dr. Martin Bar- 

 ry 1 revived a view of Dol- 

 linger, but which has met with 

 little favour, and certainly 

 needs demonstration, that the 

 blood corpuscle is the imme- 

 diate agent in the construc- 

 tion of many tissues, particu- 

 larly the muscular, the ele- 

 mentary fibre of which called 



by him Spiml.fibre may even Fragments of Striated Elementary Fibres, showing a 

 be detected in the nucleus Of Cleavage in Opposite Directions. Magnified 300 di- 



the corpuscle. Mr. Bowman 2 



U fC J J/L il~ - ' Lon gitudmal cleavage. The longitudinal and trans- 



haS amrmed, that the mUSCU- verse lines both seen. Some longitudinal lines darker and 

 lar fibre *l- T^no^f a ! der than t. he rest > and not continuous from end to end : 



"hnt if ic htr * 

 , DUt It IS Dy a 



alone, that the fibrillse are 



j m, . 



ODtamed. Hiey CIO not eXISt 



in ik/i -fiKv.^ TT -fV,*. 

 1 me nore. 16 lar- 



tVinf if r^ros 



t iat it occa- 



presents, this results from partial separation of the fibrillce. 6. Fi- 

 UDOn and within it, lonffitudi- b ril , lae > separated from one another by violence at the 

 r , , ' y>. broken end of the fibre, and marked by transverse lines 



nal (lark ImeS, along Which it equal in width to those on the fibre. "7, 8 represent two 

 11 , M 11 -p.*. :~i appearances commonly presented by the separated single 



Will generally Split Up mtO fibrill. (More highly magnified.) At 7, the borders and 



transverse lines are all perfectly rectilinear, and the in- 

 cluded spaces perfectly rectangular. At 8, the borders are 

 scall P e d, the spaces bead-like. When most distinct and 

 definite, the fibrilla presents the former of these appear- 

 ances. 2. Transverse cleavage. The longitudinal lines 

 are scarcely visible. 3. Incomplete fracture following the 

 opposite surfaces of a disk, which stretches across the in- 

 terval and retains the two fragments in connexion. The 



edge and surface of this disk a seen be minutely gra . 



happens that no dis- nular, the granules corresponding in size to the thickness 

 of the disk, and to the distance between the faint longitu- 

 Whatever IS Shown tO dinal lines. 4. Another disk nearly detached. 5. Detached 



this longitudinal cleavage; but ^ 1 ^' sh wing the sarc us ele " 



1 Philosophical Transactions, for 1842, Parti, p. 89. 



a Art. Muscle, Cyclopedia of Anat. and Physiology, July, 1842, p. 508, and Physiological 

 Anatomy and Physiology of Man, Part i., Lond., 1843. 



