XXXVill ON THE ENTOMOLOGY OF THE 
apply not less to animal than to vegetable life, for no where do the Herbivora abound more than in warm 
regions, and no where do we meet with more luxuriance of foliage, or a greater exuberance of arboreous 
vegetation, than within the tropics. As we recede from the equator, and approximate to the poles, 
temperature gradually diminishes; and probably nearly in the same proportion as heat decreases, so 
shall we find the decrease of animal and vegetable species, till we arrive at that degree of cold where 
vegetation is stunted, circulation languid, animation becomes suspended, and existence is scarcely 
tenable, if not actually destroyed. 
To obviate the effects occasioned by a low temperature, some animals burrow in the earth, and pass 
the winter in inactivity and torpor; others again, gifted with extraordinary locomotive powers, migrate 
into milder regions in quest of food, which the rigour of a brumal season and a northern climate has 
rendered precarious. It appears to me an observation worthy of attention, that at the very period the 
migratory birds visit us, Insects are already teeming into life, while vegetation has arrived at a state of 
forwardness sufficient to support, as it were, the expected increase of animal beings. We infer, then, 
that as vegetation is apparently regulated and influenced by temperature, so “animalization is in a 
measure dependent on vegetation as a secondary cause. It may naturally be expected, in & gigantic 
country like India, whose superficial area is nearly one million and a half of miles in extent, that great 
diversities of climate will be found; and when we take into our consideration the altitude of its 
mountains, surpassing in grandeur the Andes of the American world, we may expect every gradation 
of temperature which can occur, from the intense cold of the eternally snow-capped height, to the 
baneful heat of the tropical valley. The elevation of the land above the ocean, the height and direction 
of its mountain ranges promoting or checking radiation, its mighty rivers and interminable jungles, 
its soil, strata, and arid deserts, absorbing and radiating heat, exert their varied influences, and modify 
the temperature of that extensive Continent; and yet, admitting thus much, I cannot help stating an 
opinion, that according to the extent of the country, no other portion of the globe enjoys a more general 
and equable uniformity of temperature than India. This may satisfactorily be proved, provided we 
take as the basis of our argument the wide range of region, over which not individual species, but whole 
genera of Insects extend, and the general uniformity of Oriental vegetation. Before dismissing the 
important subject of temperature, I wish to offer a few remarks on the variation of heat and cold 
throughout the summers and winters in the Himalayas and in India. In the former Dr. Royle states, 
in his admirable pages, that the Flora of the Himalayas in the spring and summer of the year resembles 
that of Europe, while in the rainy season it becomes intermixed with tropic-like vegetation ; and hence 
there is a certain admixture of genera belonging to temperate and tropical climes. The change of 
temperature and of moisture producing a new vegetation, exercises a corresponding influence over the 
distribution of Insects throughout the same country ; and consequently we have reason to expect, as will 
afterwards appear in my remarks, that its entomological character is also twofold, uniting in itself that of 
both zones. This intermingling of genera of tropical and temperate regions will ever probably be found 
more perceptible in the rainy season, in advancing from the valley to the mountain height ; and perhaps 
we ought to know the results of the following researches, before we attempt to arrive at any conclusion 
respecting the distribution of animal groups in the Himalayas or in India. I would therefore suggest to 
future travellers in these magnificent regions, first, toendeavour to ascertain the differences of climate, and 
the causes which affect its temperature; secondly, to find out the average limit to which tropical forms 
extend, ‘to State where they most abound, where begin to lessen, and finally terminate ; thirdly, to note 
in what | proportions the genera of tropical and temperate climes are intermingled ; fourthly, at what 
altitude temperate forms predominate over tropical ; and, lastly, to mention as nearly as it is possible 
the range of any group of animals in preference to that of any individual species: both objects, how- 
ever, are desirable. In addition to the above desiderata, it will be necessary to note the seasons of 
Insects 
