108 
and in gretit abundance near Kockland Broad, Xorfolk, entirely 
covering both sides of a deep ditch, from ^vhich the gmvel had only 
been thrown out the previous season. I do not look on this plant 
as by any means a recent introduction, but rather that the seeds 
have been exposed to the surface after being buried fora long period 
in the soil. 
Impatienn/uha, fre([uent in Surrey and other parts ; a com])anion- 
plant to our considered native species, Imixitleug noU-me-tangere, 
the seeds of these as of all the Balsams, being distributed 
by a springing dehiscence of the carpels, which causes the 
seeds to be projected to a considerable distance. 'I'his is also the 
case with another IV^orth American species, Ojralis striefa, which 
will account for their rapid spreading; indeed, the last-mentioned 
plant is diilicnlt to eradicate after it is once introduced. Onoclea 
sengilulig, a Xorth American Fern, appears well established in the 
Channel Islands, and at York. Erigeron canadensis, on the banks 
of the Thames, is the only remaining instance which I can call to mind 
of a (‘stern importation. But I must notice the permanent intro- 
duction ol I erouica hn.rhaumii ; this is not American, but, I 
suppose. Central European. It was unknown to Smith in 1821 ; 
and I can very well I’emembor w'hen it was considered a very inn' 
plant. At the present time it is in this country, at loAst, one of 
our common species, and thoroughly establislied ; no doubt, througli 
the importation of foreign Clover .and other seeds. 
I am indebted for my information on the migration of European 
species to Americ.a entirely to a lengthened notice of the subject 
by Professor A. W. Claypole, B.A., Antioch College, Ohio. 
Ihis is a matter which can hardly’ be worked out by any of us 
on this side the Atlantic, from pereonal investigation ; and we there- 
fore must rely on information from the eye-witness and individual 
research of others. The remarks which follow will therefore be 
considered, to a great extent, as coming from the observations of 
I rofessor Claypole. Lnderncath the giant wave of human 
emigration from the so-called Old to the so-called Xew World ; 
underne.ath the busy surface-tide that has swept westward from the 
shores of Europe to those of America during the last two hundred 
