REVIEWS, 
211 
properly, and produce its characteristic secretions. The globe, as regards, 
temperature, is divided latitudinally and longitudinally into different 
sones, and the nature of the yegetation in these zones varies ; lines 
passing through places having the same mean annual temperature, are 
called Isothermal; those through places with an equal mean summer 
heat are Isotheral, and with an equal mean winter temperature 
Isocheimal. The nature of the soil influences, in some measure, the dis¬ 
tribution of plants; but the connection between different rocks and the 
plants growing on them is still obscure; it would appear that the same 
species have been, in many instances, originally placed in very widely- 
separated localities; while at other times species have been created on one 
spot and have only extended a short distance from a centre. Zones of 
vegetation are given by different authors both in a latitudinal and altitu¬ 
dinal point of view. Meyen divides the vegetation of the globe into eight 
distinct zones ; marine vegetation is also divided into zones, according to 
depth or bathymetrically. Forbes characterizes a Littoral, a Laminarian, 
and a deep-sea zone. The British flora has been divided into different 
types, both as regards latitude and altitude ; it partakes more or less of the 
characters of that of different parts of Europe, and there are certain Ame¬ 
rican forms also represented. Professor Forbes endeavours to account for 
the differences in the floras of Britain, by considering them as outposts, 
separated by geological changes from larger areas.” Part Five on Palaeonto¬ 
logical Botany. In reading this chapter we are reminded of the truth of 
Mr. Philips’s statement, that “ Geology would never, perhaps, have escaped 
from the domain of empiricism and conjecture but for the innumerable testi¬ 
monies of elapsed periods and perished creations which the stratified rocks of 
the globe present in the remains of ancient plants and animals—-so many im¬ 
portant questions concerning their nature, circumstances of existence, and 
mode of inhumation on the rocks, have been suggested by these interest¬ 
ing reliquiae; and the natural sciences have received so powerful an impulse, 
and been directed with such great success to the solution of problems con¬ 
cerning the past history of the earth, that we scarcely feel disposed to dis¬ 
sent from the opinion, that without fossil zoology and botany, or what 
is denominated Palaeontology, there would have been no true geology.’* 
This chapter on Palaeophytology concludes this work, which, on careful 
examination is, in our opinion, the best as well as the safest introduction 
to botany that could -be placed in a beginner’s hands. The difficulties 
which beset the first steps in every science, are here made as easy of com¬ 
prehension as they possibly could be ; and that this work has merited the 
esteem of the public is, we think, proved by the several editions which 
