PHYSIOLOGY OF SMOOTH AND STRIATED MUSCLE 531 



was contained in the connective tissue and interstitial spaces of 

 the preparation. 



It has been argued by Meigs and Ryan^^ from the sodium and 

 chlorine content of smooth muscle that about half the water of 

 the tissue is held by the colloids as organic water. It is very inter- 

 esting to note that the amount of sugar which diffused into the 

 muscle in Experiment 63 is less than, though not very far from, 

 the amount which would be required to bring the concentration 

 of that substance up to 7.5 per cent of the weight of the supposed 

 quantity of inorganic water in the tissue. 



Experiments 58 and 59 show that smooth muscle holds its potas- 

 sium under even rather unfavorable conditions with remarkable 

 tenacity. It is interesting to compare the results of these experi- 

 ments with those of results obtained by Urano-^ and Fahr^" 

 in more or less similar experiments on striated muscle. 



In my experiments no precautions whatever were taken in 

 preparing the muscle, or to keep it near its normal state during 

 its stay in sugar solution. The muscle was handled quite roughly 

 in separating it from the mucous membrane, and still more roughly 

 in freeing it from sub-mucous connective tissue. Each piece of 

 muscle was cut along the line of the lesser curvature in order to 

 open the stomach and then into a cardiac and pyloric portion. 

 The room temperature during the preparation of the tissue was 

 22° and the temperature of the sugar solution in which it was kept 

 varied between 22° and 25°. Finally the thin sheets of stomach 

 muscle probably presented about the same amount of surface in 

 relation to their volume as did the sartorii used by Urano and 

 Fahr. 



Urano found that about a third of the potassium of striated 

 muscle would diffuse out into a sugar solution if the tissue were 

 not carefully prepared. He accordingly used sartorii, which 

 were carefully prepared and kept in cooled and oxygenated sugar 

 solution; and, even under these conditions, the tissue lost about 

 24 per cent of its potassium in six hours. Fahr used in general 



2* Meigs and Ryan; Jour. Biol. Chemistry, 1912, xi, p. 401. 



23 Urano; Zeitschrift ftir Biologie, 1907, Bd. 50, p. 212; 1908, Bd. 51, p. 483. 



30 Fahr; Zeitschrift fiir Biologie, 1908, Bd. 52, p. 72. 



