PHYSIOLOGY OF SMOOTH AND STRIATED MUSCLE 505 



grama 



NaCl 0.65 



KCl 0.02 



CaCla 0.025 



NaHCOs . 02 



Distilled water 100.00 



The solutions generally were made up according to the method 

 of Raoult; a 7.5 per cent saccharose solution, for instance, means 

 a solution made by adding 7.5 grams of saccharose to 100 cc. of 

 distilled water. The percentages of the sohd constituents of the 

 solutions are always given in terms of the anhydrous substances. 



The sartorius has been selected as the example of striated mus- 

 cle. This muscle can be easily dissected out without injury to 

 any of its fibers, and the relations between its surface and volume 

 are about the same as in the pieces of smooth muscle to be sub- 

 sequently described. A small piece of connective tissue was 

 always left attached to the pelvic end, and the tendon with a small 

 chip of the tibia to the knee end. The preparation was handled 

 through this chip of bone. 



Most of the experiments with striated muscle are repetitions of 

 experiments which have been already carried out by Overton. 

 Those instances in which this is not the case will be particularly 

 spoken of in the text. It has been thought well to publish the 

 experiments on striated muscle, partly because Overton's work 

 has been questioned in some quarters, and partly because it is 

 often important to have a comparison between the smooth and 

 striated muscle of the same individual frog. 



The smooth muscle used in the experiments was obtained from 

 the stomach. This organ was cut open along the line of the lesser 

 curvature, and the mucous membrane was then torn loose from 

 the muscular coat. The sheet of muscle so obtained usually 

 weighed about twice as much as the sartorius from the same frog, 

 but it was somewhat thinner so that the relations between its 

 surface and volume were about the same. 



Histological examinations of frog's sartorii fixed in various 

 ways indicates that the muscle fibers make up about 75 per cent 

 of their volume. The rest of the preparation consists of connec- 

 tive tissue and of the interstitial spaces between the fibers. The 



