46 BOTANY. 
9. Coniferous Form. The Abietine are characteristic of northern regions, 
and Cupressinez of southern. 
10. The Protea, Epacris, and Erica Forms. These forms supply the 
place of Coniferze in the southern hemisphere; the Protea and Epacris 
forms occurring in Australasia, and the Erica form at the cape of Good 
Hope. 
11. Myrtle Form. Some of these, such as Melaleuca and Eucalyptus, 
characterize New Holland Scenery ; others, as Guavas, are tropical. 
12. Forms of Dicotyledonous Trees. Some, with broad and tender 
leaves, as Birch, Alder, Poplar, Oak, Lime, Elm, Beech, and Horse-chestnut, 
giving a character to the physiognomy of the colder half of temperate climates ; 
while others, with thick, leathery, and showy leaves, as Olives and Laurels, 
are characteristic of warmer climates; and a third division, with large, 
beautiful leaves, Cecropia, Artocarpus, and Astrapzea, abound in the hottest 
climates. . 
13. Cactus Form. This form is developed chiefly in America, especially 
in Brazil. 
14. Form of Succulent Plants. Seen in the Mesembryacee of South 
Africa. 
15. Lily Form. This includes Liliaceze, Amaryllidaceze, and Inidacez. 
Modifications of this form occur in warm and temperate climates. 
16. Forms of Lianas, or Climbing-Plants. These forms are chiefly 
tropical, and are illustrated by Passion-flowers, Paullinias, Aristolochias, and 
Bauhinias. 
17. Pothos Form. This is a tropical form, and is illustrated by various 
species of Aracez. 
18. Orchideous Form. This is seen in the splendid Epiphytes of warm 
climates. ‘Terrestrial species chiefly occur in cold zones. 
19. The Moss Form. 
20. The Lichen Form. Both these forms characterize cold regious 
chiefly. 
in treating of the geographical arrangement of plants, we may consider 
them under two points of view; first, as respects the horizontal or latitude 
arrangement; and second, in respect to the vertical range. The mean tem- 
perature of the earth diminishes as we travel from the equator towards 
either pole, as also in ascending to the top of a high mountain from its 
base; so that there is a certain parallelism between the horizontal range of 
mean temperature and the vertical. The same is the case in plants, as we 
shall find that the same mean temperature, whether we attain this by a hori- 
zontal or by a vertical progression, is characterized by the same vegetable 
features. 
Considering, in the first place, the horizontal range of vegetation, we find 
the following to be the divisions of Meyen, the latest authority on the 
subject :— , 
46 
