534 Seed-Breeding . [August, 
did we deem it desirable to encumber our essay with meta- 
physics, but we think that the careful reader or hearer will 
understand us in our statement that progress comes through 
variation, and not through likeness ; that whether we breed 
the vegetable or the animal, it is the laws of variation which 
we must study and apply in order to produce progressive 
results : and that the law of likeness, the “ like produces 
like ” of our books, however true as an expression which 
must be and is followed by numberless limitations, is but of 
secondary importance to the practical dabbler or expert in 
the art of breeding, to that much more important law which 
embraces the variations and fixing of strudtures and func- 
tions which have been obtained. The pendulum swings to the 
right hand and to the left with a uniform motion. Any pen- 
dulum of the same length of rod and same weight of bulb, 
under given conditions, vibrates through the same arc. 
This statement may illustrate the breeder’s proposition that 
“ like produces like.” Yet let any two of us make a pendulum 
of equal length of rod and weight of bulb at our own homes, 
and we would find that pra( 5 tically they would not move over 
the same arc, because we would use rods of different cha- 
ra( 5 ter or diversity, or bulbs of different centres of gravity, 
or would hang them differently, or would calculate the arc 
traversed under temperatures which were different. It is 
only as we understood these causes of variation that it 
would be possible to produce two pendulums whose oscilla- 
tions would compare. This may liken the ‘Maw of varia- 
tion ” which is the “ application law ” for breeders, as 
distindt from the “ like produces like,” which is a true, yet 
a “ theoretical law,” which does not admit of practical 
application without the use of the “ application law ” as 
here defined. Heretofore, the tail has wagged the dog ; we 
do not propose to stop the wag, but to have the dog wag 
the tail. Unless this point be understood breeding as a 
science will cease to progress, and, indeed, the triumphs of 
the art have come from the unconscious application of these 
fadts rather than from the course which theorists have laid 
down : — “ Variation and likeness,” not “ Likeness and vari- 
ation.” This is the new and corredt method for the study 
of the laws of breeding as pradtised. Just as cultivated 
vegetables have in a large degree been removed from the 
wild vegetation, and their different status been apprehended, 
must their breeding science leave wild nature, and come to 
a cultivated application. 
These remarks must be understood to have a close and 
pradtical bearing on the breeding of seed, for a plant, as 
