156 NEP.r.ASKA STATE ITOF/nrrT/ITl; AL SOCIETY 



which come true to name from seed. As for example the Grand Rapids 

 lettuce, the Dawson Golden Chaff wheat, the Stowell Evergreen sweet 

 corn and other grains and vegetables which are propagated under varie- 

 tal names. It is either not practicable or not possible to perpetuate such 

 varieties from year to year by asexual methods of propagation. In such 

 cases it is necessary to fix the type so that the plants will come true 

 from seed before it can properly be named as a distinct variety. 



ORIGINATION OF NEW VARIETIES. 



We have seen how plants are propagated. Let us next inquire how 

 new varieties are originated. We notice first that they may be originated 

 by sexual reproduction, i. e., from seed. They may come from mongrel 

 stock as chance seedlings which are selected and propagated either sexu- 

 ally or asexually by some one who discovers that they have sufficient 

 merit to make them worthy of being introduced into cultivation, or they 

 may come from seed which has been selected because of the excellence 

 of the parent fruit or parent plant, as for example when plant seeds from 

 the largest and finest colored fruit of some favorite variety of apple 

 in the hope of getting an improved variety in some of the seedlings. Or 

 they may be produced by crossing one variety upon another for the 

 purpose of combining in the seedlings certain excellence of both par- 

 ents. 



In any of the cases above mentioned should a desirable seedling be 

 produced it is an easy matter to perpetuate the variety if it belongs to 

 any of those kinds of plants which are propagated asexually, as Ave have 

 already seen. But if the new variety belongs to any of those kinds of 

 plants which are commonly propagated fr,om seed it becomes necessary 

 as before stated, to fix the type before it is safe to disseminate it under 

 the name of a new variety. This is done by growing generation after 

 generation of the seeds and rejecting all plants which vary from the 

 desired type. This is a process which is familiar to seedsmen; by them 

 it is called "roguing" the plants. In some cases the type may be fixed 

 within a very few generations, while with others a considerably longer 

 period may be required. 



SEED SPORTS. 



Among fixed varieties there may appear suddenly a plant quite dis- 

 tinct from the type. Even when a variety has long been known in 

 cultivation and its typo has become permanently fixed, such plants may 

 arise. Such plants may properly be called "seed sports' or "mutations" 

 if they can be reproduced true to the new type under propagation. In 

 this way certain dwarf lima beans have originated from pole lima beans 

 and certain dwarf sweet peas from taller growing varieties. If one should 

 desire to perpetuate a seed sport it generally would be necessary to gj 

 through the process of fixing the type as already described. 



