468 



MOVEMENTS VOICE AND SPEECH. 



of its strength and elasticity. Attached to the inner surface of the sarco- 

 lemma, are small, elongated nuclei with their long diameter in the direction 

 of the fasciculi. These are usually not well seen in the unaltered muscle, but 

 the addition of acetic acid renders the muscular substance pale and destroys 

 the striae, when the nuclei become distinct. 



Water after a time acts upon the muscular tissue, rendering the fasciculi 



somewhat paler and larger. Acetic 

 acid and alkaline solutions efface the 

 stria?, and the fibres become semi-trans- 

 parent. In fasciculi that are slightly 

 decomposed, there is frequently a sepa- 

 ration at the extremity into smaller 

 fibres, called fibrilla?. These, when 

 isolated, present the same striated ap- 

 pearance as the primitive fasciculus ; 

 viz., alternate dark and light portions. 

 They measure about 2g fl 00 of an inch 

 (1 fi) in diameter, and their number, 

 in the largest primitive fibres, is esti- 

 mated at about two thousand (Kolli- 

 ker). The interior of each primitive 

 fasciculus is penetrated by a very del- 



i^ofp rnprnhrnnp nlncplv en vrmi n rl i n rr 

 r ' 61V * 



the fibrillae. This arrangement may 

 be distinctly seen in a thin section of 



a fibre treated with a solution of common salt in water, in the proportion of 



five parts per thousand (Kolliker). 



Connective Tissue. In the muscles there is a membrane surrounding a 



number of the primitive fasciculi. This is called the perimysium. The 



fibrous membranes that connect together the sesecondary bundles, with their 



contents, are enclosed in 



a sheath enveloping the 



whole muscle, sometimes 



called the external peri- 



mysium. The peculiari- 



ty of these membranes as 



distinguished from the 



sarcolemma is that they 



have a fibrous structure 



and are connected togeth- 



er throughout the muscle, 



while the tubes forming 



the sarcolemma are struct- 



ureless and each one is 



. . 



distinct. 



The name now most generally adopted for the ordinary fibrous tissue is 



FIG. 151. Striated muscular fibres ; magnified 250 

 diameter. i (Sappey). 



A, transverse striae and nuclei of a primitive fascic- 

 ulus : B, longitudinal striae and flbrillee of a 

 primitive fasciculus in which the sarcolemma 

 has been lacerated at one point by pressure. 



FIG. 152. Fibres of tendon of the human subject (Rollett). 



