MECHANICS AND USEFUL ARTS. 31 



kingdom in the sea. The most interesting form of expression of the distri- 

 bution of marine life is that which parallels the perpendicular distribution of 

 plants. Edward Forbes has expressed this by defining five batnymetrical 

 zones, or belts of depth, which he calls, 1, Littoral ; 2, Circumlittoral ; 3, 

 Median; 4, Infra-median; 5, Abyssal. The life-forms of these zones vary, 

 of course, according to the nature of th-e sea-bottom ; and are modified by 

 those primitive or creative laws that have caused representative species in 

 distant localities under like physical conditions, species related by analogy. 

 Very much remains to be observed and studied by naturalists in different 

 parts of the globe, under the guidance of the generalizations thus sketched 

 out, to the completion of a perfect theory. But in the progress to this, the 

 results cannot fail to be practically most valuable. A shell or a sea-weed, 

 whose relations to depth are thus understood, may afford important informa- 

 tion or warning to the navigator. To the geologist the distribution of marine 

 life according to the zones of depth, has given the clue to the determination 

 of the depth of the seas in which certain formations have been deposited. 

 Had all the terrestrial animals that now exist diverged from one common 

 centre within the limited period of a few thousand years, it might have been 

 expected that the remoteness of their actual localities from such ideal centre 

 would bear a certain ratio with their respective powers of locomotion. With 

 regard to the class of Birds, one might have expected to find that those which 

 were deprived of the power of flight, and were adapted to subsist on the 

 vegetation of a warm or temperate latitude, would still be met with more or 

 less associated together, and least distant from the original centre of disper- 

 sion, situated in such a latitude. This, however, is not only not the case with 

 birds, but is not so with any other classes of animals. The Quadrumana, or 

 order of apes, monkeys, and lemur, consists of three chief divisions Catar- 

 hines, Platyrhines, and Strcpsirhines. The first family is peculiar to the 

 " Old World " ; the second to South America; the third has the majority of 

 its species and its chief genus (Lemur), exclusively in Madagascar. Out of 

 twenty-six known species of Lemuridre, only six arc Asiatic, and three are 

 African. Whilst adverting to the geographical distribution of Quadrumana, 

 I would contrast the peculiarly limited range of the orangs and chimpanzees 

 with the cosmopolitan powers of mankind. The two species of orang (Pith- 

 ecus) are confined to Borneo and Sumatra; the two species of chimpanzee 

 (Troglodytes) are limited to an intertropical tract of the western part of Africa. 

 They appear to be inexorably bound by climatal influences regulating the 

 assemblage of certain trees and the production of certain fruits. Climate 

 rigidly limits the range of the Quadrumana latitudinally ; creational and 

 geographical causes limit their range in longitude. Distinct genera represent 

 each other in the same latitudes of the New and Old Worlds; and also, in a 

 great degree, in Africa and Asia. But the development of an orang out of a 

 chimpanzee, or reciprocally, is physiologically inconceivable. The order of 

 Ruminantia is principally represented by Old World species, of which 

 one hundred and sixty-two have been defined; w r hilst only twenty-four 

 species have been discovered in the Xew World, and none in Australia, New 

 Guinea, New Zealand, or the Polynesian Isles. The camelopard is now 

 peculiar to Africa; the musk-deer to Africa and Asia; out of about fifty 

 defined species of antelope, only one is known in America, and none in the 

 central and southern divisions of the Xew World. Palaeontology has 

 expanded our knowledge of the range of the giraffe; during Miocene or old 

 Pliocene periods, species of Carnelopardalis roamed in Asia and Europe. 



