GROWTH AND DEVELOPMENT. 179 



This increase through excessive cell action is, of course, 

 from this doctrine of persistence of force, more or less inher- 

 itable. We are not surprised, therefore, to find instances of 

 transmission of obesity in families, or of strength, or of pecu- 

 liar traits, involving an excess of activity of cell action, as 

 mental inheritances, inheritances of milking qualities in the 

 cow, etc. When the action of growth is accompanied by the 

 action of development, it seems probable that the force is of 

 a more perfect character than is the force requisite for growth 

 alone. That is, a force sufficient for growth may not be suffi- 

 cient or of the right quality for influencing and carrying for- 

 ward an extended development. When a force is insufficient, 

 we should expect either a partial or complete failure, and also 

 that the exact form in which the failure should come about 

 would vary according to the circumstances affecting it. We 

 can thus theorize on those cases where parents of the ordinary 

 size have given birth to dwarfs and to children of ordinary 

 size. A force insufficient for development should bring about 

 an abortion, or a failure in the offspring acquiring that degree 

 of existence in which the vital powers are able to add the 

 forces requisite for completing the process for arriving at 

 maturity. A force insufficient for a vigorous growth might, 

 under peculiar circumstances, allow the developmental forces 

 to continue in the formation of the young. Durdach cites an 

 instance of one man who had eight children from the same 

 wife, of whom four were dwarfs ; and Prosper Lucas another, 

 where of six children two were dwarfs. 



Developmental and growth force, however allied, and how- 

 ever much they may influence each other, yet appear to have 

 this essential difference : growth is the absorption or gaining 

 of power through a direct increase or gain arising through the 

 presence of additional force, which is appropriated under the 

 influence of the developmental force. A process in its concep- 

 tion simple, developmental force is a concrete force, brought 

 about through complexity of environment, and its existence 

 depending largely and primarily on forces accumulated in the 

 past. As a summary, growth and developmental forces are 

 alike controlled by their past history, viewing the forces con- 

 trolling each at any particular moment as a concrete force ; 

 but the forces which regulate growth are increased more 



