NOTICES OF BOOKS. 83 



class are the parasitical Fungi, etc., which infest our cereals, and even 

 our chemical infusions, etc. 



The causes of transport are very fully discussed under this Chapter; 

 the obstacles to naturalization ] and the proofs or indications of a spe- 

 cies being naturalized. 



Under the same Chapter is included a very able critical article on 

 the Naturalized Plants of Great Britain, from an examination of whose 

 origin and limits M. de Candolle draws the following conclusions: 



1. Only about 83 species can, with any tolerable degree of certainty, 

 be stated to have become naturalized since the eighteenth century. 



2. Of these 83, 10 are North American. 



3. None of the remaining 73 can be assumed to have been im- 

 ported from islands, all being very widely distributed continental spe- 

 cies : 23 are not found wild, nor even partially naturalized in those 

 parts of the continent which are nearest to England, as Holland, Bel- 

 gium, and Western France. 



4. The 23 species, not found on those parts of the Continent nearest 

 to England, must all have been introduced by man, with seeds of 

 cereals, garden-plants, or ballast, etc. ; had birds or the winds or cur- 

 rents transported them, they would certainly have been found in the 

 intermediate countries. 



These 



species are 



Arabis Turrita, Z. Valeriana Pyrenaicaj Z. Rumex alpiuus, Z. 



Dianthus plamarius, Z. Nardosmia fragrans, Reich, Iris tuberosa, Z. 



Silene Italica, Pers. Senecio squalidus. Z. „ xiphioides, Ehr, 



Astrantia major, Z. Petasites alhus, Gartn. Crocus vemus, JFilld. 



Myrrhis odorata, Scop, Hieracium aurautiaciim. Lilium Martagon, Z. 



Lonicera Caprifolium, Z. Cjclamen hederfcfolium. Allium Ampeloprasura, Z. 



M Xylosteum, Z. Linaria purpurea, MUL „ ambiguum, Z. 



Asperula Tauriua, Z. Acanthus mollis, L, 



Of this list, 3 have spread from the Botanic Gardens of Cambridge 

 and Oxford, namely, Arahis Turrita, Lonicera Caprifolium, and Senecio 

 squalidm; and the majority of the others are plants that have been 

 much cultivated. 



5. Two species are natives of Portugal and the Azores, but are un- 

 known in Western France, viz. Sisymbrium polyceratium, L., and Alyssum 

 ^mritimum, L. ; their presence however is not therefore to be attributed 

 to the action of winds and currents ; for the first is known to be an 

 escape, and the second is a very much cultivated plant. 



