PERSISTENCE OF FORCE. 159 



filament is formed ; that is, being a highly-endowed structure, 

 it can be formed only through successive reinforcements of 

 force, or successive developments ; that is, it must pass 

 through the stated course of heredity with variation. Its after- 

 functions, or, as we may express it, the inherent power locked 

 up in these minute filaments, in man scarcely one-eight hun- 

 dredths of an inch long, indicates high endowments, just as 

 the power extracted from a lump of coal is the measure of the 

 power which was made latent in the stone form in its pro- 

 duction. This is also apparent in the close connection known 

 to exist between the nervous system and the organs of gen- 

 eration and the pLrysical lassitude following their abuse. This 

 close connection between the nervous and generative systems 

 explains some of the problems attending the study of inher- 

 itance. 



Each cell partakes, it is probable, through inheritance with 

 variation, of the changes which have taken place, and which 

 are taking place, both mentally and physically, in the body. 

 It is a concretion of possibilities derived through a long course 

 of vital changes, and which is enabled, under favorable circum- 

 stances, to transmit its accumulated powers, through union 

 with another cell, to a remote posterity. The hypothesis of 

 pangenesis demands the presence of granules or gemmules 

 which are freely circulating through the system, and which 

 are supposed to be transmitted from the parent to the 

 offspring, and which can lie dormant or become developed in 

 the generations that succeed. To me, this is inconceivable, 

 and I prefer to suggest that the law of persistence of force 

 requires that no change can take place in a cell without 

 changing the possibilities of that cell in its multiplication and 

 future development ; that each cell is the sum of all the forces 

 which have acted on it in the past and are acting in the present ; 

 that the intimate connection of the generative cells with the 

 whole body, arising through their high endowment, stores up 

 in them a greater store of possibilities, brought about by their 

 extreme complexity of environment. 



These possibilities may be looked upon as forces which are 

 modified by every antagonistic force, and, strengthened by 

 every force acting in their own direction, only require suit- 

 able conditions to become developed or affect development, — 



