104 NORMAL HISTOLOGY. 



contractile substance, are embedded within it. We 

 are unable in heart-muscle to demonstrate a sarco- 

 lemma. The fibres are grouped in bundles, which 

 are enclosed in connective tissue and supplied with 

 blood-vessels and nerves. 



TECHNIQUE. 



Sections of Heart-Muscle A bit of the heart of man, or 

 any mammal, should be hardened in Muller's fluid and 

 alcohol. Longitudinal and transverse sections are stained 

 double and mounted in glycerin. 



Isolated Heart-Muscle Cells. These are prepared in 

 the same manner as smooth-muscle cells. See page 95. 



