690 



SCIENCE 



[N. S. Vol. XLI. No. 1062 



in my preparations long before the end of the 

 first hour. 



Further, the effects of cutting across the 

 fibers or of exposing an " unnatural surface " 

 in smooth muscle may be studied experi- 

 mentally by comparing the reactions of prep- 

 arations which have been cut in many places 

 with those of others which have been cut as 

 little as possible. Such experiments show that 

 cutting has no perceptible effect after the first 

 few minutes; for the first few minutes it pro- 

 duces a very slight tendency for the prepara- 

 tion to lose fluid. Examination of the differ- 

 ences in the osmotic reactions of smooth and 

 striated muscle under different circumstances 

 shows that these differences can not be ex- 

 plained as the result either of this or of any 

 other conceivable effect of injury. Smooth 

 muscle, for instance, swells more rapidly than 

 striated muscle in Ringer's solution, but less 

 rapidly in haK-strength Ringer; it would be 

 a very extraordinary hjrpothesis that these 

 opposite differences were both the effects of 

 injury. StiU less can the swelling of smooth 

 muscle in solutions of non-electrolytes and the 

 peculiar changes of weight undergone by it in 

 double-strength and half-strength Ringer solu- 

 tion be explained as the result of injury by 

 any one who will take the trouble to make a 

 careful study of these phenomena. 



In order to obtain a preparation of striated 

 muscle comparable to my preparations of 

 smooth muscle v. Korosy pared off the surface 

 layers of a frog's gastrocnemius with a razor 

 and used the core which was left. This is, to 

 say the least, a severe test. The gastrocnemius 

 is for the most part composed of short fibers 

 which run diagonally across it and end in the 

 fascia covering its surface. The procedure 

 adopted by v. Korosy would therefore give a 

 surface largely or entirely composed of the 

 cut ends of the muscle fibers. My prepara- 

 tions of stomach muscle were covered on one 

 side by the serosa and on the other by a part 

 of the connective tissue which lies between the 

 muscular and mucous coats of the stomach; 

 these two surfaces made up about nine tenths 

 that of the whole preparation, and were cer- 

 tainly as " natural " as that which is left 



covering a striated muscle after it is torn 

 away from the skin and from the neighboring 

 muscles. 



V. Korosy tried only one experiment which 

 bears on the osmotic differences between the 

 smooth and striated muscle of the frog. He 

 immersed his muscle core in 0.23 M. saccharose 

 solution and found that it gained weight fairly 

 rapidly. It is to be presumed that lactic acid 

 was being rapidly produced over the whole 

 surface of v. Korosy's preparation,^ and it is 

 not surprising, therefore, that it should gain 

 weight in either 0.23 M saccharose solution or 

 in any other solution nearly isosmotic with 

 frog's blood. But, in view of the considera- 

 tions given above, it can hardly be supposed 

 that this experiment shows that the osmotic 

 properties of smooth and striated muscle are 

 alike. 



V. Korosy also immersed his gastrocnemius 

 cores in various hypertonic NaCl solutions, and 

 found that they lost weight in the early stages 

 of their immersion.' These results are to be 

 compared with mine on the adductor muscle 

 of the clam, which had already begun to gain 

 weight after five minutes' immersion in a 

 strongly hypertonic NaCl solution.^ My prep- 

 aration was certainly not any more injured 

 than V. Korosy's in this case, yet under com- 

 parable experimental conditions it gained 

 weight and his lost. I do not understand, 

 therefore, why he thinks that his experiments 

 with the gastrocnemius core indicate that the 

 osmotic properties of the various kinds of 

 muscle under consideration are alike, nor do 

 I understand his remark on page 173, which I 

 take to mean that we need information about 

 the changes of weight undergone by clam's 

 muscle in the early stages of its immersion in 

 hypertonic solutions. We already have de- 

 tailed information on this point.^ 



6 Fletcher and Hopkins, The Journal of Physiol- 

 ogy, "Vol. 35, pp. 261 et seq., 1907; Laquer, Zeit- 

 schrift fur physiologische Chemie, Vol. 93, p. 69, 

 1914. 



T Loc. cit., pp. 170 and 171 and Table 11. 



8 Meigs, The Journal of Biological Chemistry, 

 Vol. 17, Experiment 17, p. 97, 1914. 



9 Meigs, loo. cit., Experiments 3 and 17, pp. 95 

 and 97. 



