20 



JOURNAL OF THE PLYMOUTH INSTITUTION. 



The fact that the class of Colonists consists of species that are 

 weeds of cultivated land, and so are seldom found except when the 

 ground has been adapted for their production and continuance by 

 the operations of man, makes a British botanist regard such species 

 as strangers; for, when there was no cultivation and the entire 

 land was wood, heath, or undrained marsh, scarcely a suitable 

 habitat for a single plant of this category could have been afforded 

 by the whole country. Thus he is driven to conclude that com- 

 merce introduced them, and that agriculture has fostered them ; 

 and these opinions are confirmed by the fact that the first appear- 

 ance and subsequent naturalization of several species of the same 

 character are on record ; moreover, many at present are becoming 

 naturalized. He knows too, how species settled in this country are 

 constantly being conveyed into some of its colonies. A large 

 number of this class were doubtless introduced with grain, and 

 seeds of other kinds. Cattle may have brought others in their 

 wool or hair, as well as in other ways. Palaver Rhceas, Fumaria 

 officinalis J and Alopecurus agrestis will serve as examples of colonist 

 species. 



Among the Aliens, or certainly introduced species, of the Ply- 

 mouth Plora are Koniga maritima, Br. ; CEnothera odorata, Jacq. ; 

 Gnaphalium 7n(irgaritaceum, L. ; Polemonium eceruleum, L. ; Scrophu- 

 laria vernalis, L. ; Ilimulus luteus, L., species grown for ornament. 

 Medicago sativa, L. ; Trifolium hyhridum, L. ; Trifolium incarnatum, 

 L., plants cultivated for fodder. Carum Carni, L.; Fetroselinum 

 sativum^ Hoffm. ; Melissa officinalis, L., employed in domestic 

 economy. Lepidium JDraha, L. ; BarJchausia taraxacifolia, D.C.; 

 Barhhausia setosa, D.C. ; Crepis biennis, L.; Veronica Buxhaumii^ 

 Ten., apparently accidentally introduced, or unintentionally sown. 



The lecturer placed Viscum album (the Mistletoe) with the 

 Aliens, as he considered it had been introduced into the Plymouth 

 Flora through a mistake, and that it does not exist in the neigh- 

 bourhood, except where originally planted. 



At the conclusion of his lecture, he asked those present to take 

 into consideration the very difficult nature of his subject, before 

 they criticised his paper. 



A papey will be read on the 11th November on 



COMMON SALT. 

 By Mr. G. W. Ormerod, m.a., f.g.s. 



