460 



GENERAL MORPHOLOGY OF PLANTS 



be seen. But in the second generation of hybrids (from seed of 

 the first) tails and dwarfs were both present, and in the pro- 

 portion of twelve tails to four dwarfs.* The tails of the first 

 hybrid generation, then, contained the dwarf character as w r ell 

 as the tall character, but the tall is the dominant character 

 and prevented the dwarf from expressing itself. The dwarf 

 character was latent. 



On planting seeds of this second hybrid generation, dwarfs and 

 tails being kept separate, the dw r arfs \vere shown to be pure 

 dwarfs, and in all the succeeding generations produced nothing 

 but dwarfs. This show r ed that out of every sixteen of the second 

 generation, four dwarfs were " extracted." The dwarf character is 

 the recessive character. A study of the tails of the second hybrid 

 generation showed also that for every sixteen of the second gen- 

 eration there were four tails extracted, which thereafter always 

 produced tails. The other eight tails of the second generation 

 had both the tall and dwarf character, but in the third genera- 

 tion split up so that for every sixteen there were twelve tails and 

 four dwarfs, and so on. This can be shown by the following 

 diagram. 



Tall plant 



Dwarf plant 



* They do not always come out in such exact mathematical proportions, 

 but when the number of plants grown is large, the proportion is very close to 

 this. 



