S6 HEREDITY AND EVOLUTION IN PLANTS 



Mendel, a monk in the monastery at Briinn, Austria, where 

 he finally became abbott. In order to understand his work 

 clearly the student should familiarize himself the various 

 characters of the edible or garden pea, the chief plant with 

 which Mendel worked. 



44. Mendel's Problem. — Mendel was much interested 

 in problems concerning the origin and evolution of species. 

 It was largely this interest that led him to hybridize {i.e., 

 cross-pollinate) plants of different species and varieties, 

 and observe the behavior of the resulting hybrids in succes- 

 sive generations. The problem which he endeavored to 

 solve was the law or laws "governing the formation and 

 development of hybrids,"' with special reference to the 

 laws according to which various characters of parents 

 appear in their offspring. 



45. Mendel's Method. — He recognized that, in order 

 to solve the problem, attention must be given to at least 

 four points, as follows: 



1. To start with pure-breeding strains. 



2. To consider each character separately. 



3. To keep the different generations distinct. 



4. To record, for the progeny of each generation sepa- 

 rately, the proportions in which the various characters 

 appear. 



No previous student had recognized the fundamental 

 importance of these requirements. 



46. Choice of Material.— Mendel realized that the 

 success of any experiment depends upon choosing the 

 most suitable material with which to experiment. He 

 laid down the requirements as follows : 



' All the quotations in this chapter are from an English translation of 

 Mendel's original paper. His form of expression has been preserved as 

 far as possible, even when the "quotes" are omitted. 



