266 THE CULTURE OF FARM CROPS. 



so farmers in their methods of planting, endeavor to direct 

 the fertilization of their crops as far as they can in a gen- 

 eral manner. 



No improvement however that is at all satisfactory, can 

 be reached in this way; and so the operation of crossing, by 

 using the pollen of one variety of plant to fertilize the pis- 

 tils of another kind, is practiced. 



This is done in the following manner. 



Some plants, as has been described, have their stamens 

 and pistils borne by different individuals. Strawberries and 

 hops, are examples of this kind. With these it is a very 

 easy matter to effect a cross fertilization. All that is re- 

 quired is to protect the pistillate plants from the reach of 

 any pollen but that which is used in the operation; and by 

 taking flowers of the staminate kind, at the time when the 

 pollen is ripe and is being shed, and when the pistils are in 

 a receptive condition, and scattering the pollen over these. 

 This is all that is required to produce a new variety which 

 may differ from each of the parents in a marked degree, and 

 yet possess the better characteristics of each. 



We say may differ; because while the probability is that 

 there will be a difference, yet the tendency of reversion to 

 inferior types is so strong in nature that of ten thousand 

 seedlings not one may be any improvement upon the par- 

 ents, and yet every one may differ in some respect. At 

 the same time there may be some valuable distinct and new 

 kind which may be worth all the trouble that has been ex- 

 pended upon the remainder. This has been the case in every 

 instance, and yet the few valuable results which have been 

 gained, have enormously overpaid for the aggregate effort. 



When perfect flowers are subjected to the operation of 

 crossing, a more difficult process is required. The anthers 

 from the selected flower are cut off as soon as they appear 

 by means of a slender pair of scissors; and the end of the 

 branch with the flower, is covered with a bag of fine gauze 

 of linen or silk, to protect it from pollen other than that 

 which is desired. The flowers chosen for their pollen are 

 gathered when in the right condition and brought to the 



