54 MANUAL OF THE MOLLUSCA. 
boldt; Fabricius and Latreille have divided the world into 
climatal Insect-proyinces; and Professor EH. Forbes has con- 
structed a map of the homoiozoic belts or zones of marine life. 
To all these the remark of Mr. Kirby is applicable—that any 
division of the globe ints provinces, by means of equivalent 
parallels and meridians, wears the appearance of an artificial 
and arbitrary system, rather than of one according to nature. 
Professor Forbes has been careful to point out that although 
the ‘‘ Faunas of regions under similar physical conditions bear 
a striking resemblance to each other’”—this resemblance is 
produced, ‘‘not by identity of species, or even of genera, but 
by representation” (p. 45). 
Origin of the Natural History Provinces. Mr. Kirby appears 
to have been the first to recognise the truth that physical 
conditions were not the primary causes of the zoological pro- 
yvinces, which he ‘‘ regarded as fixed by the will of the Creator, 
rather than as regulated by isothermal lines.” * Mr. Swainson 
also has shown that the ‘‘ circumstances connected with tem- 
perature, food, situation, and foes, are totally insufficient to 
account for the phenomena of animal geography,” which he 
attributes to the operation of unknown laws.t+ 
The most important contribution towards a knowledge of 
these ‘‘ unknown laws” has been made by Professor E. Forbes, 
who was perhaps the first naturalist ever in a position to ayail 
himself of the great storehouse of facts accumulated by geolo- 
gists, respecting the distribution of organic life in ‘‘ the former 
world.”’ This subject will be referred to again in connection 
with the subject of Fossil Shells; meanwhile it may be stated 
that, according to this evidence, the Faunas of the Proyinces 
are of various ages, and that their origin is connected with 
former (often very remote) geological changes, and a different 
distribution of land and water over the surface of the globe. 
MARINE PROVINCES. 
Amongst the genera of marine shells there are some which 
have been considered particularly indicative of climate. From 
the Arctic list the following may be taken as examples of the 
shells of high latitudes; those marked * being found in the 
southern as well as in the northern hemisphere :— 
* Tntroduction to Entomology. 
+ Treatise on Geography and Classification of Animals, Lardnet’s Cabinet Cyclo 
pedia. 
