SOME FUNDAMENTAL PRINCIPLES. 37 



the services which steam and electricity have so far given. Even unconscious 

 or half-conscious plant breeding has been one of the greatest forces in the 

 elevation of the race. The chemist, the mechanic, have, so to speak, domesti- 

 cated some of the forces of Nature, but the plant breeder is now learning to 

 guide even the creative forces into new and useful channels. This knowledge 

 is a most priceless legacy, making clear the way for some of the greatest bene- 

 fits which man has ever received from any source by the study of Nature. 



A general knowledge of the relations and affinities of plants will not be a 

 sufficient equipment for the successful plant breeder. He must be a skilful 

 botanist and biologist, and, having a definite plan, must be able to correctly 

 estimate the action of the two fundamental forces, inherent and external, which 

 he would guide. 



The main object of crossing genera, species or varieties is to combine 

 various individual tendencies, thus producing a state of perturbation or partial 

 antagonism by which these tendencies are, in later generations, dissociated and 

 recombined in new proportions, which gives the breeder a wider field for 

 selection ; but this opens a much more difficult one, the selection and fixing of 

 the desired new types from the mass of heterogeneous tendencies produced, 

 for by crossing bad traits as well as good are always brought forth; the 

 results now secured by the breeder will be in proportion to the accuracy and 

 intensity of selection and the length of time they are applied. By these means 

 the best of fruits, grains, nuts and flowers are capable of still further improve- 

 ment in ways which to the thoughtless often seem unnecessary, irrelevant or 

 impossible. 



When we capture and domesticate the various plants the life forces are 

 relieved from many of the hardships of an unprotected wild condition, and 

 have more leisure, so to speak, or, in other words, more surplus force, to be 

 guided by the hand of man under the new environments into all the useful and 

 beautiful new forms which are constantly appearing under cultivation, crossing 

 and selection. Some plants are very much more pliable than others, as the 

 breeder soon learns. Plants having numerous representatives in various parts 

 of the earth generally possess this adaptability in a much higher degree than 

 the monotypic species, for, having been subjected to great variations of soil, 

 climate and other influences, their continued existence has been secured only by 

 the inherited habits which adaptation demanded; while the monotypic species, 

 not being able to fit themselves for their surroundings without a too radically 

 expensive change, have only continued to exist under certain special conditions. 

 Thus two important advantages are secured to the breeder who selects from 

 the genera having numerous species the advantage of naturally acquired plia- 

 bility, and in the numerous species to work upon by combination for still fur- 

 their variations. 



The plant breeder, before making combinations, should with great care 

 select the individual plants which seem best adapted to his purpose, as by this 

 course many years of experiment and much needless expense will be avoided. 

 The difference in the individuals which the plant breeder has to work upon are 

 sometimes extremely slight. The ordinary unpracticed person cannot by any 

 possibility discover the exceedingly minute variations in form, size, color, 

 fragrance, precocity and a thousand other characters which the practiced 



