GEOLOGY 139 



resulted in the formulation of what I shall call the Doctrine 

 of Pene-Planation, or the Doctrine of the Cycle of Land- 

 Form Development. According to this doctrine all land areas 

 pass through a series of stages in their development that cor- 

 respond roughly to the stages in the life of the higher forms 

 of organic beings. Each land area has a stage of birth when 

 it is brought up from the sea bottom or other similar position 

 through the operation of constructive forces. This is fol- 

 lowed by stages of infancy, youth, adolescence, maturity, old 

 age, and final extinction. These stages are passed through 

 by all land areas during their development, regardless of 

 their initial form or height. The particular forms assumed at 

 each stage vary with the nature of the body's anatomy, this 

 being due to the operation of constructive processes. In gen- 

 eral the infantile stages of all land forms are characterized 

 by great simplicity. The development through youth to ma- 

 turity consists in a gradually increasing complexity of form, 

 reaching a maximum in that respect at maturity. Thencefor- 

 ward the development takes the form of gradually decreas- 

 ing complexity and increasing simplicity, reaching finally in 

 extreme old age a stage comparable to that of extreme in- 

 fancy — one of extreme simplicity — the stage of second child- 

 hood. The stage of youthful simplicity, however, is one with 

 potentialities in it; that of old-age simplicity is one without 

 potentialities. This is expressed in their respective elevations. 

 The youthfully simple land form lies well above the zero 

 level, or death level, so to speak, of land activity — that is to 

 say, well above sea level. The land form in the stage of old- 

 age simplicity lies very near the zero level ; in other words, 

 it lies near sea level. The land meets extinction gradually 

 through the slow decrease of its vital forces. Its period of 

 old-age simplicity may last much longer in time than all the 

 previous stages that it has passed through. In the case of the 

 organic being, however, nature is more merciful. It does not 

 permit of the lingering death due to an infinitesimally slow 



