A DYNAMICAL HYPOTHESIS OF INHERITANCE. 47 



cylinder of a nerve-cell, owing to very unequal surface-tensions 

 developed in one or more directions so as to draw it out into 

 a condition of equilibrium, in assuming which it acquires a 

 great length. Formal changes in cells, no matter how irregu- 

 lar these may become, must be due to alterations of surface- 

 tension due to molecular transformations at certain points on 

 the surface of globular or polyhedral embryonic cells. The 

 final mature form of a cell is a consequence of the assumption 

 of a statical equilibrium amongst its parts, due to the nature 

 of its metabolism and its consequent molecular structure. The 

 statogenetic factors of development are therefore of just as 

 much importance as the kinetogenetic, or those involving 

 motion. The statical forces that are developed in individual 

 cells also act reciprocally between all of the cells of the organ- 

 ism, so that in this way the effect of statogeny extends through- 

 out the entire organism. 



If there were no such statical forces to be overridden by the 

 purely kinetic ones developed by the molecular transformations 

 and consequent motions incident to metabolism, provided the 

 latter, together with assimilation, took place, during develop- 

 ment, with great rapidity, the ontogeny of an organism would 

 take place with such swiftness that it could not be successfully 

 studied by embryologists. In other words, ontogeny would 

 take place in the twinkling of an eye, and organisms as large 

 as whales might even mature in an instant, provided the coef- 

 ficients of viscosity and surface-tension of their plasma were to 

 fall nearly to zero, while assimilation and metabolism proceeded 

 with infinite rapidity. 



It follows also from what has preceded that we can now 

 form some idea why apparent rejuvenescence occurs in every 

 ontogeny. Every germ must, for assignable reasons, begin its 

 existence in the original, highly complex, aeolotropic condition 

 of the plasma of its species. It must therefore begin its 

 career somewhat in the guise of the mechanically unspecial- 

 ized plasma of a remote unicellular ancestor. Unlike that an- 

 cestor, however, the cells that result from its growth and seg- 

 mentation cohere until a multicellular aggregate results, the 

 different regions of which fall into certain statical states in 



