32 A ddress of the President. 



Commerce and agriculture have also been the means of 

 introducing many species, some of them not always useful. A 

 fresh-water shell (Dresseina polymorpha), a northern species, 

 has been introduced into many of the English canals and 

 waters. A most noxious plant, Anacharis alsinastrum, has 

 lately found its way to this country, and its growth is so rapid 

 that it has in some instances filled up canals and stopped the 

 navigation. Ballast from foreign vessels emptied on the shores 

 has introduced many plants not before known. Foreign 

 wood has introduced both plants and insects. Foreign field and 

 garden seeds have also borne their part ; the dodder (Guscuta), 

 sometimes so hurtful to the crops of clover, is one of these ; and 

 foreign hay is another carrier of seeds. Now, the geographical 

 distribution of animals and plants, and their mode of getting 

 or of being transported from one place to another, is a very 

 interesting inquiry, and in the questions and speculations of 

 the present times it is assuming a wide importance ; to all 

 these changes, both of former and present days, the members 

 of the Society must direct their attention. 



As already stated, the combination of indoor ineetings in 

 winter, and country excursions in summer, I think is an ex- 

 cellent arrangement. One of the primary objects of the 

 Society is to elucidate the history and resources of the district 

 within its range, and without the latter this could not be done. 

 In winter I do not think our papers should be restricted to 

 British or local subjects. The comparison of the works of 

 man — whether buildings, weapons, or utensils for the field or 

 home, or of works of art — will be found most useful wherever 

 they may come from, and many of our members may go to 

 far-off countries, and observations on the productions of these 

 will often open up a more varied discussion ; but in the publi- 

 cation of our proceedings and transactions, beyond the title 

 or a very short abstract in the former, we should confine our- 

 selves to papers relating to local history and productions only. 

 I would wish them to be a record of the condition now of our 



