58 DYNAMICS OF LIVING MATTER 



is large. From this Bernstein justly argues that Imbert's assumption 

 is incorrect, inasmuch as the area required for the work the muscle 

 really does, must be much larger than that between the fibrils and the 

 neighboring liquid. Bernstein therefore assumes that the fibril consists 

 of a row of quite small ellipsoids, whose long axis is in the direction of 

 the fibrils, and whose form is determined by elastic forces. An increase 

 in the surface tension must make these ellipsoid elements more spherical, 

 and thus the fibril becomes shorter and thicker. 



How can the nerve impulse or an artificial stimulation of the muscle 

 increase the surface tension? There are several possibilities. Sub- 

 stances might be formed in this case which increase the surface tension 

 at the limit between Bernstein's hypothetical ellipsoids and the surround- 

 ing liquid. Another possibility might be that, through the process of 

 innervation or stimulation, an existing difference of electrical potential 

 between the ellipsoids and the surrounding liquid might be diminished. 

 D'Arsonval explains the efficiency of electrical stimuli in this way.* 

 Hermann has offered another hypothesis ; namely, that the contrac- 

 tion is a process of coagulation, and the relaxation, a process of lique- 

 faction.f He was led to this idea by the fact that the change in form 

 which the muscle undergoes in the case of rigor mortis is similar to 

 that in contraction, and that moreover a number of other features are 

 common to both. Although all these hypotheses concerning muscular 

 contraction have been known for a number of years, none has led to a 

 new discovery. The reason lies possibly in the fact that one or more 

 links in the catenary series of processes which underlie muscular con- 

 traction have been ignored in these hypotheses. It is well known that 

 a muscle gains in mass through " contractions, and that it undergoes 

 atrophy when it remains at rest. This fact indicates, in my opinion, 

 very clearly that phenomena or reactions which directly or indirectly 

 lead to growth form a part in the process of muscular contraction. 

 I consider it quite possible that no hypothesis concerning muscular 

 contraction will prove fertile until this relation between activity and 

 growth of the muscle is recognized. 



3. CONCERNING THE THEORY OF CELL DIVISION 



Were scientists with a purely physical training to be asked to give a 

 hypothesis concerning cell division, I believe that their hypothesis would 

 not take into consideration the phenomena of growth. Nevertheless, 

 these phenomena form an obvious link in the catenary series of processes 



* D'Arsonval, Archives de physiol., 5th series, Vol. I, p. 460, 1889. 

 t Hermann, Handbuch der Physiologic, Vol. i, Part I, p. 332. 



