C^e ^ylogettf of t^e Cot?ietion* 



Harold L. Lyon 



A theory concerning the phyloge- 

 netic origin of any plant structure must 

 necessarily be, in major part, but spec- 

 ulation, for in such discussion one can 

 not determine all the factors which 

 may have induced the mutations, nor 

 keep in view all the transitional stages 

 which led up to the ultimate organ. 

 Any reasonable hypothesis well grounded 

 on observed facts may be offered as a 

 contribution to science, since it fur- 

 nishes a basis for the correlation of 

 facts. The results of investigations as 

 they are recorded from time to time 

 do not stand out as simple isolated 

 facts, but through existing theories help 

 to explain and interpret other phe- 

 nomena. 



57 



