OKLAHOMA ACADEMY OF SCIENCE 29 



different manner. 



Mentally his traits were those of slow but penetrating analysis, 

 of tenacious persistence, amounting almost to obstinacy, and espec- 

 ially of the power of pursuing an abstract idea. That his experi- 

 ments were carefully thought out and planned may be seen from 

 the following quotation from his chief work, the paper on peas. 



"Those who survey the work done in this department will 

 arrive at the conviction that among all the numerous experiments 

 made, not one has been carried out to such an extent and in such 

 a way as to make it possible to determine the number of different 

 forms under which the offspring of hybrids appear, or to arrange 

 these forms with certainty according to their separate generations, 

 or definitely to ascertain their statistical relations." 



"It requires indeed some courage to undertake a labour of 

 such far-reaching extent ; this appears, however, to be the only 

 right way by which we can finally reach the solution of a question 

 the importance of which cannot be over-estimated in connection 

 with tlie history of the evolution of organic forms." 



"The value and utility of any experiment are determined by the 

 fitness of the material to the purpose for which it is used, and 

 thus in the case before us it cannot be immaterial what plants are 

 subjected to experiment and in what manner such experiments are 

 conducted. 



"The selection of the plant group which shall serve for experi- 

 ments of this kind must be m'ade with all possible care if it be 

 desired to avoid from the outset every risk of questionable results. 



"The experimental plants must necessarily — 



1. Possess constant differentiating characters. 



2. The hybrids of such plants must, during the flowering 

 period, be protected from the influence of all foreign pollen, or 

 be easily capable of such protection. 



The hybrids and their offspring should suffer no marked dis- 

 turbance in their fertility in the successive generations. 



"Accidental impregnation by foreign pollen, if it occured dur- 

 ing the experiments and were not recognized, would lead to entirely 

 erroneous conclusions. Reduced fertility or entire sterility of 

 certain forms, such as occur in the offspring of many hybrids, 

 would render the experiments very difficult or entirely frustrate 

 them.. In order to discover the relations in which the hybrid forms 

 stands towards each other and also towards their progenitors • it 

 appears to be necessary that all members of the series developed 

 in each succesive generation should be without exception, sub- 

 jected to observation. 



