Theory and Practice in Breeding. 173 



the parts and constructing a unit. The first great 

 problem is : "How can the desirable characteristics of 

 two or more parental kinds be picked out and blended 

 into a group of progeny and at the same time discard 

 other characters which we do not desire." Another 

 problem : "How so to blend two kinds as to create en- 

 tirely new valuable characteristics or to create increased 

 values in existing characteristics/' 



When two differing organisms are united and all of 

 the dominant and atavic elements of each are thrown 

 together the most complex synthesis takes place. There 

 is ample proof that all characteristics of both ancestors 

 are inherited, though only a part of the mass of these 

 inherited characters can be dominant, effective and vis- 

 ible in any one progeny. There is not room for all ; 

 some must remain as dormant atavic elements. 



The complexity of characteristics of each of the 

 parents may crudely be likened to a rope of 10,000 

 threads, of a thousand kinds of colors, each of a dif- 

 ferent strength, no two colors or strengths represented 

 by the same relative number of threads. . The rope thus 

 becomes a complex whole, made up of characteristic 

 parts ; and a large group of similar ropes becomes the 

 variety, breed or species. 



A river may further serve to illustrate that the liv- 

 ing organism is made up of very many active correlated 

 forces acting and reacting upon each other and upon 

 their surroundings. Place in the flowing water 10,000 

 chemical compounds in varying proportions. There 

 will at once be formed many stable compounds, some of 

 which will remain in solution and may be termed active 

 or dominant; others will be insoluble and will sink as 

 insoluble or atavic elements to the bottom of the river, 

 but always there and ready to arise when their affinities 

 are better satisfied by some passing substance than those 

 which hold down the elemental substances. If we could 

 now divide the broad stream into many streams with 

 narrow islands between, it would roughly represent the 

 race blood or the species blood divided into as many in- 



