MICHIGAN ACADEMY OF SCIENCE. 
27 
ably no two Individuals are ever quite alike, variation is 
universal and a “species of plant is a judgment of man.'’ Still the 
conception of species is too useful to be lost. Species do exist, but 
as averages, norms or even conditions and a sport, form, variety or 
mutation simply means the extent and nature of the departure from the 
norm. 
Now as the characters of a plant — other than those acquired during 
life — are generally inherited, the selection of the seed of those plants 
that have desirable variations and the rejection of undesirable seed 
will result in a better average crop. We can commonly move the average 
in any direction in which variations occur and by continuous selec- 
tion maintain it there. This is plant breeding in its simplest form and 
as such has been practiced for centuries and is still in common use. 
The method ignores the discoveries of recent years but its great results 
entitle it to respect and may justify its coni 'nuance. 
There is one method that has been practiced for centuries by which 
man has caused variation and increased his chances of favorable selec- 
tion. This is hybridizing. Most of our cultivated plants are hybrids. 
Often we do not know the parent species and when we do know them 
we are ignorant of the proportions in which the ancestral strains exist. 
Probably cross pollination was often an accident as far as man was 
concerned. In practice it has been and still is largely an empirical 
subject. Breeders have been able to construct an average of probabilities 
as to what will and what will not occur in a given case; but the given 
case may contradict all the probabilities without apparent cause. We 
do not know what forms will hybridize or when this is accomplished 
if the hybrid will be fertile. Crosses often increase the vigor of the 
strain, hybrids between more remote forms are less likely to show this 
and may deteriorate. When crossing has been accomplished we do 
not know what we may get, because of our ignorance it is a matter 
of chance. What we are pretty certain to get are a lot of new combina- 
tions from which selection can be made, and that multiply many fold 
the opportunities of the breeder. 
As an example of this method the history of some well known hybrid 
will be of interest. The sweet pea seems to have been first cultivated 
in 1G99 by Father Fraud sens Cupani, a botanist of Sicily, where a 
purple and a white species are indiginous. Seeds were sent by him 
to England and elsewhere. As early as 1750 they had become an article 
of commerce. Two new species were brought from the island of Ceylon, 
a red and a pink and white still known as the “painted lady.” From 
these four wild species it is probable all our sweet peas are derived. 
In 1795 a London seed catalog offered five varieties. Forty years later 
two more — a striped and a yellow — appeared. Not until 1800 do we 
find any further advance, when a blue-edged variety known as the 
“Butterfly” was added. The next few years gave us the “Invincible,”— 
a scarlet, — the “Crown Princess of Prussia,” — the first flesh pink, 
“Adonis,” — a rose pink, — and a few others of less worth. In 1870 
Henry Eckford of Shropshire, England, took up the sweet pea prob- 
lem. Starting with a few common sorts it was seven years before he 
had anything to offer, but by 1898 he had put out seventy-five named 
varieties, the result of twenty-two years selection. Others were also 
at work and so from small beginnings the marvellous variety of size, 
