LABORATORY DIRECTIONS. 467 



sets the bone may be mounted dry by covering 

 with circular cover glass, which sticks to the ring of 

 balsam. 



2. Sections of decalcified bone. Place a fresh 

 bone in 95 per cent, alcohol to fix and harden soft 

 parts. Next day begin process of decalcification. 

 Use nitric or hydrochloric acid, ^ to i per cent., using 

 a large quantity and changing fluid twice daily. 

 Nitric acid may be used in i to 10 per cent, strength. 

 Time required varies from one to seven days. By 

 means of sharp needles it is possible to determine 

 when decalcification is complete. After decalci- 

 fication wash in running water for twenty-four hours. 



Muscle. 



1. Smooth muscle. Pieces stripped from the 

 intestinal wall may be stained for twenty-four hours 

 with dilute hematoxylin. Tease in glycerin and 

 alcohol, or, for permanent mounts, dehydrate and 

 tease in oil. 



2. Cross sections of the intestine will show smooth 

 muscle in cross and in longitudinal sections. 



3. Heart muscle. Teased specimens and very 

 thin sections. 



4. Voluntary muscle. Sections of a tongue will 

 show fibers both in cross and in longitudinal section. 



5. Injected muscle. Sections should be cut very 

 thick to show capillaries. Such muscle carefully 

 teased is very satisfactory. 



6. Fresh voluntary fibers may be teased in 

 alcohol and glycerin. 



Nervous Tissue. 



i. For bipolar cells study sections of the spinal 



ganglion. 



