50 Development and Distribution of Vegetation. 
But these views have been greatly modified by further examination. It is 
noted that nearly all our troublesome weeds are foreigners. These are trou- 
blesome in the fields, gardens and waysides because of their vigor of growth, 
their tenaceous hold upon the soil, and their enormous powers of multiplica- 
tion. Of course these things could not exist without adaptation to the condi- 
tions, and without, to them, favorable surroundings. It has not unfrequently 
happened that plants of comparatively feeble development in their native 
country have become conspicuously vigorous when introduced by man else- 
where. We have an often cited, but excellent example in a little water plant 
found in all our streams by those who search for it,—scarcely noticeable in 
any other way —called Anacharis Canadensis. This was taken in some way in 
a living state to England and placed in one of their rivers. To the astonish- 
ment and no doubt in a short time disgust of the introducer it proved to be a 
noxious weed, growing and multiplying wonderfully, choking the water 
courses and demanding in some cases large expenditures for removal. It is 
undeservedly known as Babington’s curse. A like result followed the intro- 
duction of the edible watercress from England into Australia. Three intro- 
duced plants have taken possession (like the white man of America crowding 
out the natives) of the plains of California; but, in this case, they are wel- 
come as pasture herbage. The common plantain, a pest of door-yards was 
called by the Indians the white man’s foot. Our cereals (except maize) and 
garden plants are natives of the Old World, and the same is true of our 
orchard fruits; yet no country in the world produces apples equal to those 
grown in some parts of America. The common potato originally grew upon 
the mountains of Chili. Who could have predicted its renowned develop- 
ment in the moisture-laden atmosphere of an island in another hemisphere and 
across a great ocean? If it is objected that cultivation by man secured these 
results, then mark the wide-spread and abhorred cardoon thistle on the pam- 
pas of South America. The fact is, plants grow where they can, and as they 
can, subject to existing conditions and surroundings; but no one can predict 
how any species will behave under other circumstances and upon other soils. 
Remembering now the immense antiquity of plants and even of most of the 
present species, and taking the great geographical features of the world as, 
upon the whole, similar to what they now are, with an abundant variation in 
detail and great changes of climate, let us endeavor to solve by way of illus- 
tration, a few problems which the present distribution of vegetation presents. 
In this we need not stop to inquire why arctic plants are not found in tropical 
climates, nor why the special vegetation of brackish swamps is not met with 
upon sandy, inland plains; but why rather special groups of plants grow 
where they do and not in other equally favorable localities. If we could read 
upon their leaves the eventful story of descent to our times, every way-side 
weed, as well as every forest tree, would furnish us with most fascinating in- © 
formation in which would come out in one way or another, not only the his- 
tory of weeds and trees; but of the creation and migration of man. Ay! we 
should read of One above man, who from the beginning marshalled according 
to His will, the whole ftretch and scope of all history. Tennyson says:— — 
“Flower in the crannied wall, 
I pluck you out of the crannies, 
Hold you here, root and all in my hand. 
Little flower; but if I could understand 
What you are, root and all, and all in all, 
I should know what God and man is.” 
Dr. Gray has given usin an admirable biography something of the story of the 
giant red woods of California. Our abstract cannot do this story justice, but a 
few words from it are eminently appropriate in this place. There are two 
