11^ NOTICES OF BOOKS. 



evident. The Eomans, in the days of Pliny, cultivated many vaiieties 

 of Pears and Plums. Homer distinguished Poppies with black and 

 white seeds. The Egyptians cultivated white-seeded Sesamim. The 

 Hebrews distinguished the stveet and bitter Almond ; and the black 

 and white Grape appear to be of great antiquity. Hence it appears 

 that perhaps too much influence is attributed to cultivation, which 

 effects many small changes, whilst truly hereditary races are always 

 veiy ancient ; that is to say, they date from a peiiod that is altogether 

 prehistoric, if indeed they are not older than the art of cultivation. 



What appears equaUy curious is, that certain cultivated plants which 

 are so closely allied that it is doubtful whether they are species or va- 

 rieties, as the two Guavas, Psidium pomifermi and pijrifenim, the sweet 

 and bitter Orange, the Peach, and Nectarine, are also of very con- 

 siderable antiquity. 



^^ Chapter 10 is devoted to the study of what M. de Candolle calb 

 " Especes disjointes," or species whose individuals are disconnected by 

 large exi>anses of land or water, but which cannot have been trans- 

 ported from one country to the other on account of the size or struc- 

 ture of their seeds, or of some obstacle presented by their habits of life. 

 These come under three principal categories:-]. Woody plants with 

 bulky seeds, that are not littoral ; 2. Presh-water plants ; and 3. Moun- 

 tain plants. 



The facts here adduced are very numerous, well arranged, and some 

 of them most curious ; and though very often discussed, have hitherto 

 met with no plausible exi)lanatiou j perhaps the most striking are, that 

 of Enocaulm septangulare, which is confined in the Old World to a 

 very hw spots in the extreme west of Ireland and Scotland, but which 

 IS common in North America from Newfoundland to the Saskatchawau 

 KiyGV-—Phryma leptoslachya, L.,* a native of the mountains of Nepal 

 and the United States of America j— and SpirantU, cernua, Rich., found 

 m one spot m the south of Ireland and in the Northern United States 

 and Canada, etc. With regard to the Phryma, M. de Candolle inclines 

 to the hypothesis of a double creation, whilst he thinks the Eriocauhn 

 may have been transported at a remote period, when the plant had a 



s^M ?v uo n^^^ I '°"p "'' ^^y''''' ^^'''' 1"^^ ''"<1 ^^^ C'^^t <^o«st of Asia ab- 



woS Sii «,^^^ ''^ '■'° <^-^tremely difficult j.laut to find in the 



*ooas It luhubits. aud may be mucli moic co.umoa than is usually supposed. 



