VAI;I vi [OH AND IIKKI.MTY 



6 not the result of ino.lifi.-ational -iTVrta may viv- 

 i.lly I. i-in- .'.Mm,, ill.- fact that tin- species is dividing into 

 two sub-species."* Tim-. iy means of - 

 seems the dryest of all methods, we Hre able to see a 



iei U-iug born under our very eyes. 



point we havr ju-t maoS- shows how a species 

 might originate by the accumulation of extremely slight 





PlOUBE 2. Curve of Pi-ti il>utim. 



variations. But evidence is at hand to 41 sliow that or- 

 gani. bure may pass with seeming abruptness from 



one position of njuilil.rium to anoth-r." Changes of con- 

 M-i.-rable amount sometimes occur at a single leap. 

 Mi.U.-M jumps or hanges are called "discontinu- 

 ous \ us," or sometimes, "sports," and, in certain 

 cases, "mutations." Professor Hugo de Vries has made 

 some very interesting and impo? \|M'riiufiits and 

 obsei - on tin* oriiriu of sp'fi's in tin* plant king- 

 He found that species often arU< from one an- 

 other 1'Y <li^(-ontinuou< traps and bounds as opposed to 

 the continuous pr Ho therefore believes that 



Thornton & Ckddtc, op. !.. pp. 121-122. 



