PLANT VARIATION UNDER WILD CONDITIONS. 



427' 



they reach the adult stage. The result is that any advantage possessed 

 by a variety or species in the way of robuster or quicker growth gives it 

 a material advantage over its associates even in its infancy, and it is a 

 common occurrence for the thus favoured occupants of a pan of a mixed 

 sowing, to overgrow and destroy their fellow sporelings of a less assertive 

 character, unless these be removed to another pan. Hence it is quite 

 obvious that the struggle for existence does not take place before any 

 varietal or specific characters exist, and that ' beneficial or favourable 

 characters ' are existent when the destructive period occurs. 



The seeds of Phanerogams also undoubtedly show their specific, 

 varietal, or constitutional differences at an early stage of development, 

 and consequently my Fern experiences form a fair parallel and not an 

 exceptional case. 



