ADDRESS. lxxxi 
the individual families of plants must be either peculiar to, or decidedly pre- 
dominate in, such region. 
So defined, the surface of the earth has been divided into twenty-five re- 
gions, of which I may cite as examples that of New Zealand, in which Ferns 
predominate, together with generic forms, half of which are European, and 
the rest approximating to Australian, South African, and Antarctic forme : 
and that of Australia, characterized by its Euculypti and Epacrides, chietiy 
known to us by the researches of the great botanist, Robert Brown, the 
founder of the ‘Geography of Plants.’ 
Of the heaths, or heath-like shrubs, some genera, Hrica, or true heath, for 
example, characterize the Cape of Good Hope and Europe; other genera 
the Cape and New Holland; others again, as Epacris, Lissanthe, and Leuco- 
pogon, are characteristic of Australia. 
The vegetable kingdom has been classified into many such physiogno- 
mical groups. The latest botanical statistics make 213,280 species ; but the 
best informed botanists believe that we are still acquainted only with a small 
proportion of existing plants. 
Geographical Distribution of Animais—Organic Life, in its animal form, 
is much more developed, and more variously, in the sea, than in its vegetable 
form. 
Observations of marine animals and their localities have led to attempts 
at generalizing the results; and the modes of enunciating these generaliza- 
tions or laws of geographical distribution are very analogous to those 
which have been applied to the vegetable kingdom, which is as di- 
versely developed on land as is the animal kingdom in the sea. Certain 
horizontal areas, or provinces, have been characterized by the entire assem- 
blage of animals and plants constituting their population, of which a consider- 
able proportion is peculiar to each province, and the majority of the species 
_ have their areas of maximum development within it. 
Of such provinces of Marine Life, that much-lamented, far-seeing, and 
genial philosopher, Edward Forbes, has provisionally defined 25. 
The same physical conditions are associated with a certain similarity be- 
tween the animals of different provinces. Where those provinces are proxi- 
_ mate, such likeness is due to the identity or close affinity of the species ; but 
where the provinces are remote, the resemblance is one of analogy, and spe- 
cies of different genera or families represent each other. 
A second mode of expressing the ascertained facts of the geographical 
_ distribution of marine animals is by tracts called ‘ Homoiozoic Belts,’ bounded 
_ by climatal lines, which are not, however, parallel with lines of latitude, but 
undulate in subordination to climatal influences of warm or cold oceanic 
4 currents, relations of land to water, &c. Of these belts, Professor E. Forbes 
has defined nine : one equatorial, with four to the north and four to the south, 
which are mutually representative. 
~— But the most interesting form of expression of the distribution of marine 
1858. I 
