134 ELEMENTARY BIOLOGY. [CHAP. 



toplasm lodging a number of fusiform deeply- 

 staining nucleate bodies (tnuscle corpuscles}, 

 b. The muscular fibre; structural analysis. 



i. Tease out gently a bit of muscle from a freshly- 

 killed animal, and examine in salt solution with 

 i inch obj. 



a. Composed of elongated fibres, which exhibit, 

 unless the fibre be quite fresh, a tendency to 

 split up into finer filaments (so-called fibrilltz). 

 ft. The sarcolemma; visible as a superficial clear 

 layer of the fibre ; expansions of it may be 

 seen at points where the continuity of the 

 fibre has been interrupted by pressure, or 

 other cause of rupture. 



ii. Examine with a high power. 



a. The alternate lighter and darker bands placed 

 transversely to the long axis of the fibre 

 (transverse striatioti). 



ft. The sarcolemma ; enveloping the fibre ; seen 

 here and there as a delicate film, where the 

 fibre is twisted or bruised. 



y. The muscle corpuscles ; visible as elongated 

 and slightly refractive fusiform bodies, dis- 

 posed longitudinally. 



iii. Treat with acetic acid ; the striation is rendered 

 very indistinct, the sarcolemma and muscle cor- 

 puscles becoming very conspicuous. Add a 

 drop of magenta ; the nuclei stain deeply. 



iv. Transfer a fragment of fresh muscle fibre to a 

 slide bearing a drop of salt solution, and tear it 

 into small shreds with a couple of needles. 



