BROOKLYN BOTANIC GARDEN 
LEAFLETS 
THE BROOKLYN INSTITUTE OF ARTS AND SCIENCES 
Series VI Brooklyn, N. Y., April 17, 1918 No. 2 
ENVIRONMENT, VARIATION AND THE 
LAWS OF HEREDITY 
“The organic world as a whole is a perpetual flux 
of changing types .” — Francis Galton. 
Infinite, endless variety is the most striking fact about the 
world in which we live. As though from a huge magic box, an 
Aladdin’s cave, so to speak, new types of plant and animal life 
constantly issue forth. You see them in your gardens as vegeta- 
ble, fruit, or floral novelties, or at the flower shows as new carna- 
tions, roses, or orchids. You see them in the plant-breeders’ 
gardens, at the trial grounds of the great seed-houses, in the 
breeding pens of stock-raisers, or at the fanciers’ shops. And 
last you meet them on the street as friends, especially if you be 
a citizen of one of those great pioneer countries such as the 
United States, Argentina, or Australia, where the shackles of 
tradition are still mere threads, and the “melting pot” accepts 
almost all “comers.” No corner, however minute and obscure, 
of earth’s vast stretches of sea and land lacks in diversity of 
animate form or color to those with the seeing eye. And this is 
as true of the vast deserts and the tiniest bits of pond-mud as it 
is of the verdure-clad tropical river valleys of Brazil or Central 
Africa, where life, even to the most superficial observers, appears 
kaleidoscopic. 
So seldom is one of nature’s forms duplicated, that even when 
an approach is made to it, as in the case of identical twins and 
the so-called “doubles” in man, the greatest wonderment is ex- 
cited. Our neighbors and acquaintances are alike only in a few 
so-called fundamental characters. We have no difficulty, as a 
rule, in distinguishing them, even at a distance, or often without 
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