Ml-. R. B. Hinds un Geographic Botany. 28 



America, Rhizubulece, Mununiieci^, Simarouhiacrce, Voclujaccfp, Ca- 

 lijcerccB, Escalluniea.', Humiriacece, Laciatemece, Pajtayuceo', Gillie- 

 sieie, Gesnerece ; in Australasia, Tremandrea, Baueracece, Epaai- 

 deie, Guodenovife, Slack/iuiisetp, Brunincea ; being thirty-one in 

 number, or an eiglith ])art of the wh(jle. 



In addition to the geographical divisions here followed, there 

 is another which may be regarded as accessory to it. In the 

 present instance the distribution of heat has been the leading 

 consideration, which is well known, as a general rule, to diminish 

 from the equator to the poles. The first region extends from the 

 equator to the limits of the tropic in the northern hemisphere, 

 or 23° 28' N.L. The second is comprehended in the space be- 

 tween this and the parallel of 40°N.L., and is called the sub- 

 tropic; the next extends from 40° to 60°N.L., being the tem- 

 perate ; and the last or arctic comprises all the surface north of 

 60°. As the regions are repeated in the southeni hemisphere, 

 the whole are necessarily eight in number; the north tropic, 

 south tropic, north sub-tropic, south sub-tropic, north temperate, 

 south temperate, arctic and antarctic. The last is scarcely more 

 than a nominal region, though it still claims a few terrestrial 

 plants and some Alga^, which make its existence necessary. 



Inquiries have sometimes been made as to what are the most 

 prominent sources of difference in the character of the vegetation, 

 or of the composition of the respective floras, of the two hemi- 

 spheres. To afford some illustration of this, those families are 

 here enumerated which are more particularly distinguished for 

 having the mass of their numbers in one or the other. Those 

 families already mentioned as confined to one division have been 

 omitted, as the repetition would only occupy useful space. The 

 south tropic families are usually to be found in the Brazils, 

 whilst the south sub-tropic, as Oxalidece, Diosmece, Proteacece, 

 Pohjgalece, are chiefly from the Cape of Good Hope, New Hol- 

 land and South America. The list might be very easily enlarged, 

 but our object is only to furnish the most striking. 



In the northern hemisphere are predominant, Acerinea, Au- 

 rantincecE, Artocarpeoe, Ameniacece, Berberidea, Boraginecs, Caryo- 

 phyllece, Cistinece, Cnicifera, Conifera, Cupuliferce, Campanula- 

 cea, Caprifoliace(P, Dipsacecp, Elceagnea, Fumariacece, Grossulacece, 

 Hypericinete, Hippocastanea, HamamelidecE, Magnoliacece, Ona- 

 grarite, Orobanchece, Papaveracea, Rosacece, Baminculacece, Ruta- 

 cea, Resedacea, Saxifragece, Umbelliferce, Vaccinece, Alismace^. 



In the southern hemisphere are predominant, Atherospermea, 

 Cactete, Crassulacetp, Capparidece, Diosmece, Dilleniacece, Ficoidece, 

 Geraniacece, Heliotropiacece, Myrtacece, Melastomacece, Myoporinece, 

 Malpighiacece, Oxalidece, Pittosfjorac, Pohjgalea;, Proteucea, Sea- 



