1 6 THE GLORY OF THE GARDEN 



do thus meet in fertilisation, the product of their 

 union is pure, thus showing that the behef, held for 

 so long, that purity of type depends on continued 

 selection has no physiological foundation. For 

 the homozygous individuals, which are the only 

 ones that will breed true, may appear in F2. It is 

 the business of the breeder to find these individuals, 

 and by continued selection, he may perhaps succeed 

 in the end, for at each selection he increases his 

 chance of finding them; but by following the 

 Mendelian method he can go straight to the point, 

 and thus, very probably, save himself many years' 

 work. 



Technical Methods. 



The actual work of crossing plants together is 

 quite simple, but at the same time it demands 

 much patience and concentration. 



In the first place, the anthers of the plant to be 

 used as a female must be picked out carefully with 

 forceps before they are ripe. The flower is then 

 covered to exclude insect visitors. 



Muslin bags may be used for this purpose, but they 

 are not so safe as rainproof bags made of parchment 

 paper. The bag is put over the flower, the mouth 

 being crushed up so as to fit the stem, and it is 

 fixed in place with a thin piece of copper wire. 

 Bees vdll often visit flowers covered over with muslin, 

 and it is difficult to prevent this. The flower from 

 which pollen is to be taken must also be covered 

 before it opens, in order to keep its pollen pure 

 and unadulterated. 



The old-fashioned method of using a brush for 

 the transference of the pollen is not advisable; it is 



