108 CROSS-BREEDING 



And, ipso facto, wrinkledness and green are recessive, and 

 when a group of recessive characters are combined in one 

 plant that plant breeds true; it cannot do otherwise. 



The pursuance of this matter opens up the subject of 

 gametic coupling and other fine facts of embryology. The 

 gamete is " a unisexual protoplasmic body, incapable of 

 giving rise to another individual until after conjugation 

 with another gamete, the joint production being a zygote." 

 The latter is therefore the body or germ, produced by fer- 

 tilization, and this tiny protoplasmic mass in the ovule 

 carries in it certain of the characters of the parents. 



The Sweet Pea raiser must exercise great discrimination 

 and have abundance of patience. He must select the most 

 likely parents, for haphazard crossing rarely produces 

 anything meritorious. He must never cross two weak 

 varieties, and he must avoid as much as possible those 

 varieties that have certain failings, for such failings are 

 invariably dominant in the offspring. 



