Energy in Animals 43 



contrary, it is a wise precaution to assume 

 that energy, accumulated at a given stage in 

 growth or cellular change, will tend to confine 

 itself to that stage and will resist change to a 

 different stage. All resistance, however, will 

 yield to the application of force, and the 

 amount of yield will vary directly as the 

 amount of energy expended and inversely 

 as the magnitude of the resistance. From 

 this we may argue that if the energy ex- 

 pended to produce an accumulation comes at 

 a different time in the life of an individual 

 from that at which it came in the preceding 

 generation, this change in the application 

 might force the inherited accumulation to- 

 ward the new time in life. Hence, if a stal- 

 lion accumulated a large amount of energy 

 by reason of a large amount of work per- 

 formed shortly after becoming sexually ma- 

 ture, and that accumulated energy became 

 sexual in character by reason of the time in 

 life at which it was accumulated, then if the 

 son of that stallion should perform a large 

 amount of work before becoming sexually 



