12 ZOOLOGY OF INDIA. 



we are familiar, or pertain to groups which are themselves 

 well exemplified by European species. Among the Him- 

 maleh mountains, however, and other southern portions 

 of this division, we discover many of the genera which 

 occur in the low lands of Hindostan, and the peninsular 

 projection of Malacca. The same circumstance indeed 

 occurs, — we mean the like transition of species, — in all 

 the great geographical sections of animal life. Each ex- 

 tensive division is characterized by several pecuhar forms, 

 and yet at the same time nourishes many species which 

 are common alike to it and to other regions ; and it is only 

 under some peculiar circumstances of local situation that 

 either the zoological or botanical products undergo a sudden 

 change in character and condition. As the adventurous 

 and observant traveller advances on his journey, a few 

 species are continually perceived to decrease in numbers, 

 and then to disappear, — while their places are supplied by 

 others, which, at first but thinly scattered, gradually acquire 

 an accession of numbers, till they too have reached their 

 full amount or centre of dominion ; but the change bemg 

 only partial from place to place, the difference is no more 

 suddenly perceptible than that in the horizon by which the 

 traveller is himself surrounded, and a portion of which in 

 his onward progress becomes insensibly firom the circum- 

 ference the very centre of the field of vision. 



Many species indeed can scarcely be said to have any 

 proper centre of dominion, but are rather repeated again in 

 different and far-distant regions ; thus showing that certain 

 peculiar combinations in the physical character and consti- 

 tution of countries, which we cannot always perceive or 

 appreciate, lead to an analogous character among the tribes 

 of living nature, almost independent of latitudinal or longitu- 

 dinal position. These latter circimistances, however, — that 

 is to say, the position of a place in relation to latitude and 

 longitude, especially when combmed with a knowledge of its 

 height above and distance from the sea, — are on a general 

 view highly influential in regulating the distribution of 

 species, and form, if not an mdispensable, at least a highly 

 interesting element m our knowledge of the geography 

 of natural groups. Although under similar climates the 

 species may be singularly diversified, yet an identity, or 

 close resemblance of specific forms, may no doubt be relied 



