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characters. The people of some countries are more hybridized 
than those of other countries. Great Britain, France and the 
United States are excellent examples of much _ hybridized 
peoples, while Denmark and Sweden perhaps are fair illustra- 
tions of the lesser hybridized peoples. Modern transportation 
has vastly increased the mixing of peoples and the marriage of 
all sorts of types, so that the existence of people pure in the 
greater proportion of their hereditary characters is largely 
mythical. 
With peas it is different, for they naturally inbreed, whether 
wild or tame. What mixing has occurred has largely been 
brought about by man in his efforts to produce new and better 
varieties. The varieties, once created, are made to breed true. 
Otherwise they would be of little value to gardens and canneries. 
Civilized man demands only one type of pea in a can or in the 
measure of peas he buys from the green grocer. So the great 
majority of pea plants in the world are comparatively “ pure.” 
That is they breed true to their parent and ancestral line. Thirty 
generations of peas from one pea family, picked at random, lined 
up side by side would look very much alike. Their individual 
differences would be largely environmental. But in thirty gen- 
erations of human beings from one family, say one American 
family picked at random, the differences would appear enor- 
mous. In the first case, an expert associated with peas all his 
life could not tell them apart. In the second, a child in its sixth 
year would have no difficulty in distinguishing them. 
Peas do have great diversity, however. There are thousands 
of varieties. At the U. S. Experimental Sub-station at McMil- 
lan, in northern Michigan, 1,100 valuable commercial varieties 
are being grown this year, and at the Brooklyn Botanic Garden, 
in our breeding work, we have grown over 500 varieties, com- 
prising all the most bizarre types, collected from all over the 
pea-growing world. Then each year we produce thousands of 
new types, of which varieties could be made, but it would serve 
little purpose, since most of them are neither better nor worse, 
commercially speaking, than those already in existence. 
“How do peas differ?” asks the layman, especially those lay- 
men reared in the cities. At the green grocers peas are only 
