STATISTICS OF VEGETATION. 677 



and violets, delight in the clear skies of suh-tropical regions. Hinds 

 gives the following tabular view of the relative proportion of colours : 



Cyanic. Xantiic. White. 



Central America ... 12 . . . 30 ... . 

 Sandwich Islands . .. 12 .... 31 .... 7 



Alashka 26 . . . 13 . . . 11 



California 25 . . . . 19 . . . 6 



New Guinea 12 .... 23 .... 15 



Hong-Kong 13 .... 27 .... 10 



■Geyer says that vivid colours mark the basaltic plains of Upper 

 Oregon ; blue and purple, eastward ; scarlet with golden-yeUow, west- 

 ward ; glaucous green reigns in the herbage over the plains ; deep 

 saturated green in the valleys. 



Statistics of Vegetation.— The number of known vegetable 

 families differs in different latitudes. In examining the distribution 

 of the great classes of the Vegetable Kingdom, it will be found that 

 certain relative numerical proportions have been ascertained. It is 

 not easy to estimate the proportion which Oryptogamous bear to 

 Phanerogamous plants. From data already given it may be estimated 

 that the proportion for the whole world is as 1 to 7. This proportion 

 varies in different regions ; the Oryptogamous plants increasing in 

 their proportion in the northern parts of the temperate zone. Ferns 

 are to known Phanerogamous plants as 1 to 20. This proportion is 

 least in the middle of the temperate zone, and becomes larger towards 

 the equator, and towards the poles. Ferns, however, attain their 

 absolute maximiun at the equator, and their absolute minimum in the 

 arctic zone. At North Oape there are only four species of Ferns 

 found, and yet their proportion to Phanerogamia is 1 to 7 there ; and 

 in Greenland 1 to 10 (Meyen). Humboldt says that in the torrid 

 zone Monocotyledons are to Dicotyledons as 1 to 6 ; in the temperate 

 zone, as 1 to 4 ; and in the arctic zone as 1 to 3. Monocotyledons 

 increase in proportion to Dicotyledons as the latitude becomes higher. 

 Some natural orders are very generally diffused, as Leguminosse, Mal- 

 vaceae, Eanunculacese, OaryophyUacese, Oruciferse, and Umbelliferse. 

 Cellular plants have also a wide range, and so have aquatics. Jun- 

 •caceae, Oyperacese, and Graminese, increase in proportion to all the 

 Phanerogamous plants, as the latitude becomes higher ; while Resti- 

 acese, Leguminosse, Euphorbiacese, and Malvaceae, decrease. Oruciferse, 

 UmbeUiferae, and Oompositae, are highest in their proportion in the 

 temperate zone, diminishing towards the' equator and the poles. Hinds 

 gives the following statement as to certain families which are almost 

 exclusively confined to one of the six great divisions of the globe : — 



In Europe — Globulariaceas a section of Selaginaces, Ceratophyllacese. 



In Asia — Dipterocarpaceae, Aquilai-iacese, CamelliacesE, Moringaceie, Stilagin- 



2,cex. 



