106 PRACTICAL HISTOLOGY [XIII 



fibres into osmic acid 0'5 p.c. or into absolute alcohol : good 

 specimens may thus be obtained from the crayfish and the 

 reversal of the bands in contracted muscle seen. 



The fibres are readily isolated by placing in 35 p.c. potassium 

 hydrate for 20 minutes and then shaking. 



A saturated solution of ammonium carbonate has been 

 recommended to show the sarcolemma (a few minutes), and to 

 cause transverse cleavage (six hours). 



Staining. Teased muscle may be stained with haematoxylin, 

 treated with acid alcohol and mounted either in dilute glycerine 

 or in balsam. In extended muscle, the thick and thin discs are 

 stained ; in dytiscus leg muscle the lines of sarcoplasm will also 

 be distinct. Strips may be stained in very dilute Kenaut's 

 heematoxylin and eosin for half-a-day to a day; care must be 

 taken not to wash out the eosin in mounting. 



Branched muscle fibres may be obtained from the tongue of 

 the frog. 



Preparation for polarized light. Stretch the muscles, and 

 pin out, place in 50 p.c. alcohol for half-a-day to a day, pass 

 gradually through the grades of alcohol, tease, clear with clove 

 oil and mount in balsam. 



