INTRODUCTION OF FOREIGN WEEDS. 5 
“ Queries in Local Topographical Botany,” published in the 
‘ Transactions of the Plymouth Institution and Devon and 
Cornwall Natural History Society,’ writes : “ I have en- 
deavoured to show that the investigation of local phenomena 
may be undertaken with a view to the solution of scientific ques- 
tions of the utmost importance and greatest magnitude ; that 
evidence supplied by local facts may be used to support or 
weaken — possibly to prove or disprove— some of the startling 
theories of the age.” 
These two quotations afford much guidance and encourage- 
ment for the Members of the Selborne Society, who, without any 
very prolonged special training, are endeavouring to substitute 
systematic study of natural objects for mere haphazard ob- 
servations without any connecting link. The special subject 
which I would suggest in this present paper, as a means by 
which those principles may be applied, is the systematic obser- 
vation of the establishment and subsequent increase or de- 
crease of aliens in the shape of foreign weeds. When it is 
remembered that a very large number of exotic plants from 
similar climates to our own are continually being introduced into 
this country, and when one remembers also that our own “ ne’er- 
do-weels ” have often spread with tremendous rapidity after 
transportation to foreign climes, one might be inclined to dread 
lest the foreign element might in many instances overcome and 
supplant our own natives. These patriotic fears may be safely 
set aside ; the instances in which the immigrants eradicate the 
home-dwellers are comparatively few in number. 
Kew Gardens, perhaps, afford the best means of deciding this 
question. Did the immense number of plants introduced there, 
from places with similar climatic conditions to our own, establish 
themselves in the neighbourhood with the audacity which is 
sometimes ascribed to them, Kew would be a sort of centre of 
contagion from which would be disseminated all manner of 
foreign weeds, supplanting and disturbing our native flora. But 
hardly anything of the sort ever occurs. Few, very few, of the 
exotics in the vicinity have held their own against the rightful 
owners of the soil for many successive years. Most of them — 
some prolific enough and apparently well-fitted to survive — 
scarcely appear a second season. It is very interesting to watch 
the more or less rapid crowding-out of these strangers by the 
hardier and more persistent natives. Probably the whole of the 
thoroughly-naturalised foreigners in the flora of the neighbour- 
hood could be counted on the fingers. One plant — a Composite 
( Galinsoga parviflora), introduced to Kew from Peru some forty 
years ago — has, however, proved its ability to hold its own in 
cultivated ground, and even to oust, to a great extent, our native 
ubiquitous groundsel. In Germany, too, particularly in some of 
the great seed-growing districts, it has become such a perfect pest 
that laws have been made to prevent its further spread, and if 
possible to destroy it. The magistrates of Hanover, in 1865, 
