The basic principle of Burbank's plant magic comes under two heads, viz.: breeding and selection. He mates two different species in such a way that they will propagate a type partaking of the natures of both but superior to either in their qualities. In order to effect the best results from mating, he is choice in his selection of species--the best is taken and the worst rejected. It is a universal law that the bad can never produce the good; consequently when good is desired, as is universally the case, bad must be eliminated. In his method, Burbank gives the good a chance to assert itself and at the same time takes away all opportunity from the bad. So that the latter cannot thrive but must decay and pass out of being. He takes two plants--they may be of the same species, but as a general rule he prefers to experiment with those of different species; he perceives that neither one in its present surroundings is putting forth what is naturally expected from it, that each is either retrograding in the scale of life or standing still for lack of encouragement to go forward. He knows that back of these plants is a long history of evolutions from primitive beginnings to their present stage just as in the case of man himself. 'Tis a far cry from the cliff-dweller wielding his stone-axe and roaming nude through the fields and forests after his prey--the wild beast--to the lordly creature of to-day--the product of long ages of civilization and culture, yet high as the state is to which man has been brought, in many cases he is hemmed in and surrounded by circumstances which preclude him from putting forth the best that is in him and showing his full possibilities to the world. The philosopher is often hidden in the ploughman and many a poor laborer toiling in corduroys and fustian at the docks, in the mills, or sweeping the streets may have as good a brain as Edison, but has not the opportunity to develop it and show its capabilities. The same analogy is applicable to plant life. Under adverse conditions a plant or vegetable cannot put forth its best efforts. In a scrawny, impoverished soil, and exhausted atmosphere, lacking the constituents of nurture, the plant will become dwarfed and unproductive, whereas on good ground and in good air, which have the succulent properties to nourish it the best results may be expected. The soil and the air, therefore, from which are derived the constituents of plant life, are indispensably necessary, but they are not the primal principles upon which that life depends for its being. The basis, the foundation, the origin of the life is the seed which germinates in the soil and evolves itself into the plant.