528 EDWARD B. MEIGS 



the end of two or three hours the tendon kept at the lower tem- 

 perature begins to gain faster than the other. In the case of the 

 smooth muscle, on the other hand, the swelhng is slower at the 

 lower temperature through the whole six hours of the experiment. 



The swelling of tendon in 0.7 per cent NaCl solution does not 

 differ much from that which takes place in Ringer's solution. 

 Three experiments were carried out in which pieces of tendon were 

 immersed for from nineteen to twenty-four hours in 0.7 per cent 

 NaCl solution at temperatures varying between 18° and 21°. 

 At the ends of the experiments the pieces of tissue weighed 14.5 

 per cent, 18.2 per cent and 20.4 per cent more than originally, 

 the average gain being 18 per cent. The weight of the three pieces 

 of tissue increased gradually throughout the course of the experi- 

 ment; there was no tendency toward a rapid gain followed after 

 three to six hours by a loss, as there is in the case of smooth muscle 

 immersed in 0.7 per cent NaCl solution. Experiment 40 gives the 

 details of the change of weight undergone by tendon in 0.7 per 

 cent NaCl solution. 



In 7.5 per cent cane sugar solution, tendon gains weight to about 

 the same extent as in Ringer (Experiment 29). And in distilled 

 water tendon gains weight very much less than does smooth mus- 

 cle and not very markedly more than in Ringer's solution (Experi- 

 ment 41). • 



Tendon swells less in Ringer without NaHCOa than in ordinary 

 Ringer (Experiments 38, 42, 43 and 47) . But if small quantities 

 of lactic acid be added to the Ringer without NaHCOs the tendon 

 swells markedly more than in Ringer (Experiments 39 and 44). 



SUMMARY OF THE RESULTS SO FAR DESCRIBED 



In the preceding pages the changes of weight undergone by 

 smooth muscle in various solutions has been compared, on the 

 one hand, with the reactions of striated muscle, and on the other, 

 with those of tendon. The results are in full accord with the prev- 

 alent view that the surfaces of the living striated muscle fibers 

 are highly impermeable to salts and sugars. The results with 

 smooth muscle and tendon, however, indicate that no considerable 



