Chap. X. PREPOTENT TOLLEN. 397 



" have land engaged in the growth of seed in no less 

 than eight parishes." The mere fact of a vast number 

 of plants belonging to the same variety growing 

 together is a considerable protection, as the chances 

 are strong in favour of plants of the same variety inter- 

 crossing ; and it is in chief part owing to this circum- 

 stance, that certain villages have become famous for 

 pure seed of particular varieties.* Only two trials 

 were made by me to ascertain after how long an interval 

 of time, pollen from a distinct variety would obliterate 

 more or less completely the action of a plant's own 

 pollen. The stigmas in two lately expanded flowers on 

 a variety of cabbage, called Ragged Jack, were well 

 covered with pollen from the same plant. After an 

 interval of twenty-three hours, pollen from the Early 

 Barnes Cabbage growing at a distance was placed on 

 both stigmas ; and as the plant was left uncovered, 

 pollen from other flowers on the Ragged Jack would 

 certainly have been left by the bees during the next 

 two or three days on the same two stigmas. Under 

 these circumstances it seemed very unlikely that the 

 pollen of the Barnes cabbage would produce any effect ; 

 but three out of the fifteen plants raised from the two 

 capsules thus produced were plainly mongrelised : and 

 I have no doubt that the twelve other plants were 

 affected, for they grew much more vigorously than the 

 self-fertilised seedlings from the Ragged Jack planted 

 at the same time and under the same conditions. 

 Secondly, I placed on several stigmas of a long-styled 

 cowslip (Primula veris) plenty of pollen from the same 

 plant, and after twenty-four hours added some from a 

 short-styled dark-red Polyanthus, which is a variety of 



* With respect to Messrs. Sharp, p. 823. Lindley's ' Theory of Hor- 

 see ' Gardeners' Chronicle,' 1856, ticulture,' p. 319. 



