386 THE CANADIAN NATURALIST. [DeC. 



E. commutitta, Engel., lias been noticed at Shannonville, Out., 

 by Macoun, who remarks its introduced-like appearance. 



Salix lucida, Muhl., is very common in the ditches and moist 

 grounds on the sides of railway tracks. It is abundant through- 

 out the two Provinces. 



Panicum capillar e, L. 



When the Provinces were originally settled by the ancestors of 

 the present French population, we can believe that many of the 

 weeds of France found a home here. Immigration during suc- 

 ceeding years from the same country, and from Great Britain and 

 Germany, not only repeated the introduction of many of these 

 weeds, but largely swelled the number of introduced species. 

 At the present day, our close commercial relations with Great 

 Britain and the United States are producing a yearly influx of 

 these unwelcome visitors, and scattering them broadcast over the 

 country. Though new forms only now and then make their ap- 

 pearance, there is an incursion — renewed every summer to a 

 greater or less extent — of those familiar, self-made friends of 

 ours. At the same time, not only are these very species — along 

 with some members of our indigenous flora — migrating from 

 here and obtaining a footing in other foreign lands with 

 which we are in commercial intercourse, but they must fre- 

 quently reappear among their native brethren, in the countries 

 from which they originally came. Amongst those countries be- 

 tween which trade relations are intimate, there must be a con- 

 stant interchange in this way. 



Illustrative of this immigration from different countries, there 

 may be cited : from tropical America, Senebiera didyma, Pers., 

 which occurs at Gaspe, and Montreal, and which has, probably, 

 been directly introduced, Chenopodium amhrosioides, L., species 

 of Amaranthus, of which there is presumption that they have 

 come by way of the United States, and Nicotiana rustica, L., 

 which Dr. Gr;iy considers a relic of cultivation by the Indians; 

 from the United States, Martjjnia prohoscidea, Glos., probably 

 Acalyplia Virginica, L., and some of the Euphorbias, and from 

 Europe, in addition to many well-known plants, PotentUJa argen- 

 tea, L., Leontodon autumnale, L., Plantago lanceolata, L., Pu- 

 mex patientia, L., and (lynodon Dactylon, Pers. 



The large yearly influx of population from different parts of 

 Europe aids materially in establishing species throughout the 

 Provinces, and the facilities afforded for the subsequent distribu- 



