12 THE GLORY OF THE GARDEN 



called Fj. From the fact that the character 

 tallness appears in the cross-bred, to the exclusion 

 of the opposite character, Mendel called it a 

 dominant character ; dwarfness, which disappears 

 in the Fj plant, he called recessive. 



The tall cross-bred was then allowed to bear 

 seeds by self-fertilisation, and these are the next 

 generation, F2. When grown up they prove to be 

 mixed, many being tall, and some being short, like 

 their grandparents. Upon counting the numbers 

 of this F2 generation, it was discovered that the 

 proportion of tails to shorts showed a certain 

 constancy, averaging about 3 tails to i short, or 

 75 per cent, dominants to 25 per cent, recessives. 



These F2 plants were again allowed to fertilise 

 themselves, and the offspring of each plant was 

 separately sown. It was then found that the off- 

 spring F3 of the recessives consisted entirely of 

 recessives, and further generations bred from these 

 recessives again produced only recessives, therefore 

 they are proved to be true to the recessive character 

 of dwarfness. 



But the tall F2 dominants, when tested by a study 

 of their offspring (Fg), instead of being all alike, as 

 were the dwarfs or recessives, prove to be of two 

 kinds, viz.: (i) Plants which give a mixed F3, 

 consisting of both tails and dwarfs, the proportion 

 showing again an average of 3 tails to i dwarf. 



(2) Plants which give tails only, and are thus 

 pure to tallness. 



The ratio of the first to the second was as 2 to i. 



In his original paper on plant breeding, Mendel 

 states that at the very outset he paid special atten- 

 tion to the family Leguminosce^ on account of their 



