MICHIGAN ACADEMY OF SCIENCE. 
25 
the publication of researches in heredity, in hybridity and in variation 
of quite unprecedented importance. The practice of plant breeding had 
in the past been purely empirical. No laws seemed to govern the appear- 
ance of varieties or the result of crosses. The breeder searched for 
improved races among a confusion of forms quite uncertain as to what 
he might find, or when found, if the improvement could be fixed. The 
evolution of our domestic plants is more creditable to human patience 
than to human knowledge. But tho we have been working in t lie dark, 
light is breaking. The extremely complex laws that govern the evolu- 
tionary process are now partially known, already they are influencing 
practice and when more fully understood the effect will be of the 
greatest importance and value to mankind. It was the evolution of 
our domestic races, the artificial selection of plant and animal breeders 
that was so largely used by Darwin to establish the law of natural selec- 
tion and the theory of organic evolution. If practice can thus contrib- 
ute to theory reciprocity is to be expected, for plant breeding is simply 
evolution under partial human control. 
The practice of plant breeding in its simplest terms is the selection 
of desirable varieties. The factors are variation and selection, and 
of these variation is the more critical. Selection is the human factor 
but ineffective without variation to work with. Before taking up varia- 
tion we may satisfy ourselves as to man’s ability as a selector. 
The power of discrimination may be developed in the man who lives 
among his plants to an extent almost beyond belief. To find among 
thousands of young plants the slight variation which may lead to an 
improved strain is no easy task. Often plants must be selected not 
by one but by a combination of characters. Still more remarkable is 
the ability to select plants not by the desired quality itself but by 
associated characters. Children who work in the flower gardens of 
France are able to separate the stocks that will have single or double 
flowers when they are still seedlings, even tho the seed came from the 
same parent. Quinces have been selected before they had either flowers 
or fruit. Verio t mentions a gardner who conld distinguish ISO kinds 
of Camellia when not in flower, and according to Darwin, it is posi- 
tively asserted that the famous old Dutch florist Voorhelm, who kept 
about 1,200 varieties of hyacinth, was hardly ever deceived in knowing 
each variety by the bulb alone. 
For successful work the trained eye will not suffice but an ideal must 
be in the mind of the breeder. The selection must be made, as oppor- 
tunity offers, towards a desired type. The end to be attained may be 
a development, a suppression, or a change. It may be in color, size, 
strength, height, shape, flavor, perfume, hardiness, time of maturing, 
resistance to disease, resistance to drought, absence of spines, doubling 
of flowers, or what not. And no matter what it may be still the plant 
must be considered as a whole, for a single weak point may spoil a dozen 
good ones. 
But the methods of modern agriculture will not long be satisfied 
with simple observation. At the Svatyf experiment station — which has 
become a model for breeding of grains to the whole world — the most 
exact methods of weighing and measuring are used, the qualities are 
all subject of measurements and tests by various tools and instruments, 
the vernier and the microscope are none too fine for the purpose. The 
