SEPTEMBER 10, 1897.] 
digenes, have by this important agency be- 
come dispersed over nearly all of the civil- 
ized parts of the globe, while thousands of 
other species have been carried thousands 
of milesfrom their native homes, and have 
established themselves and flourished, often 
with a new vigor, in a new soil and with 
a novel environment. i 
It is obvious that this agency is readily 
separable into two divisions : a, intentional; 
b, accidental. 
a. Intentional Importations. Since early 
times strange plants and animals have been 
carried home by travelers. Conquering 
armies have brought back with the spoils 
of conquest new and interesting creatures 
and useful and strange plants. With the 
discovery of America and with the era of, 
cireumnavigation of the globe such intro- 
ductions into Europe of curious and useful 
species, plants in particular, increased many 
fold, while with the colonization of America 
and other new regions by Europeans there 
were many intentional return introductions 
of Old World species conducive to the wel- 
fare or pleasure of the colonists. Activity 
in this direction has been increasing and 
increasing. Public botanical gardens and 
many wealthy individuals in all quarters of 
the globe have hardly left a stone unturned 
in their efforts to introduce and acclimatize 
new plants, particularly those of economic 
importance and esthetic quality, not failing 
occasionally, it must parenthetically be 
said, to establish some noxious weed, or 
some especially injurious insect; while it 
is safe to say that probably the majority of 
the desirable plants of Europe which will 
grow in the United States have already 
been introduced, and that there has been 
an almost corresponding degree of activity 
in the introduction of desirable plants from 
the United States into Europe. In all this 
host of valuable introductions there have 
been comparatively few which have turned 
out badly, aside from failures of establish- 
SCIENCE. 
383 
ment. The wild garlic (Allium vineale), that 
ubiquitous plant which gives its taste to 
milk, butter, and even to beef during the 
spring and summer months in many of our 
States, is said to have been intentionally 
introduced by the early residents of Ger- 
mantown, Pennsylvania. The water hya- 
cinth (Piaropus crassipes), originally grown 
for ornament in a pond near Palatka, 
Florida, escaped into the Saint John’s river 
about 1890, and has multiplied to such an ex- 
tent as to seriously retard navigation and to 
necessitate government investigation. The 
distribution of the orange hawk-weed (Hiera- 
cium aurantiacum), a dangerous species which 
has ruined hundreds of acres of pasture land 
in New York of recent years, was originally 
aided by a florist as a hardy ornamental 
plant. The European woad-waxen (Genista 
tinctorium) was early introduced at Salem, 
Mass., in fact about thirty years after the 
settlement of the colony. It has apparently 
not been used as a dye plant, but for garden 
and ornamental purposes only. During the 
last few years it has become a noxious weed 
throughout Hssex and the adjoining coun- 
ties. Standing on a rock at Swampscott on 
July 9th, last, the writer was able tosee that 
the country for miles around was colored a 
bright yellow with enormous masses of this 
plant. Similar instances are fortunately 
rare and the majority of our noxious weeds 
have been accidental introductions. 
Intentional introductions of animals, 
however, have by no means resulted as ad- 
vantageously as intentional introductions 
of plants, with the exception of the truly 
domesticated species, such as the horse, ass, 
cow, sheep, pig, dog, cat, poultry, honey 
bee and silk worm of commerce. Hven 
with such species, the grazing ranges of 
Australia have been overrun by wild horses 
to such an extent that paid hunters shoot 
them at a small sum per head, and the 
European rabbit has become a much worse 
plague on the same island continent. 
