BOA. 



539 



degree iu the same substance, but that in no two differ- 

 ent substances does it vary according to the same law. 

 Thus, even the boa, all-formidable as it is, dwelling 

 in places where miasmata are foul, and life brought 

 into danger from the tainted air, even if there were 

 danger of no other kind, has got a lesson to teach 

 those who will take the trouble of studying it, and 

 that lesson is of more extensive and more useful 

 application than many which are obtained from more 

 inviting creatures in more healthy localities. Follow- 

 ing out our observation a little, we find that this law 

 of the range of temperature which an animal can bear, 

 being equal from tiie mean toward greater cold and 

 toward greater heat, is not a barren or an isolated law, 

 but one which is intimately connected with the phy- 

 siological character of the animal, and varies with 

 i/i her variations, not in the larger divisions only, but 

 in different individuals of the same species, even in 

 those of the human race. The range of endurance of 

 temperature appears to be always in proportion to 

 the energy, or perhaps we may say the development, 

 of life, the rapidity of the circulation and respiration, 

 and the readiness of the animal for whatever action 

 best suits its organisation ; and we know that the 

 capacity for constant action in the animal, and the 

 necessity of frequent supplies of food, arc also in 

 proportion to these. Animals which have this sreneral 

 activity of system do not become heavy after their 

 meals, and however the cold pinches, though they 

 sometimes shiver, they do not become dormant. They 

 are thus the busy creatures. In this their general 

 habit they make the nearest approximation to man's 

 power of enduring all climates ; they are conse- 

 quently the best fitted, in their physical constitution, 

 for domestic purposes, and their dispositions are in 

 accordance ; they are the most docile, the most 

 obedient, and the most gentle in their manners. The 

 ruminantia among mammalia, and the gallinidae and 

 pigeons among the birds, are familiar instances. 



Thus, when we come to compare the animals, race 

 by race, with each other, we find the adaptation to 

 savage and civilised countries as perfect as that to 

 different climates and different kinds of surface. The 

 nature of the savage animal is fitted only to the 

 savage land ; and when man takes possession, cul- 

 tivates, and then alters the physical condition, the 

 savage creature, which would be inconvenient to 

 man, were it to remain in his neighbourhood, finds in 

 this physical change, to which its stubborn nature 

 cannot accommodate itself, that the country which 

 man has thus changed by his culture is no longer its 

 country, and it fades away, and gradually disappears, 

 leaving only its bones in the soil, to testify what the 

 country once was, and to what it may again return, 

 if man shall slacken the hand of his cultivation. 

 There have been some very striking instances of this 

 return of savage animals to places from which they 

 had been expelled by cultivation in the modern 

 history of India. After those intestine wars which 

 had left so many parts of that land of powerful natural 

 action without inhabitants, the jungle overran the 

 fields, and hid every vestige both of culture and of 

 human habitation ; and along with the jungle, the 

 larger species of the cat tribe, the tyrants of the 

 sultry wilds, multiplied in vast numbers, and abso- 

 lutely appeared to increase faster than one would 

 have, from the previous state of the country, supposed 

 to be their proper rate of increase. Even the lion, 

 whose presence at all in that part of the world, at 



least for some centuries, had become a question, was 

 found in no inconsiderable number: so energetic 

 and so active in concert are the powers of wild 

 nature. 



But that portion which is more peculiarly valuable 

 to man in a state of civilisation follows the law of 

 civilisation, and increases with its increase. This is 

 apparent not only in the animals, but in the. plants 

 upon which those animals feed ; and thus, when we 

 take our survey upon the broad and unfettered 

 principle, we not only see that all the parts of nature 

 act in" harmony with each other, but that the whole 

 act so much in concert with man, and so strengthen 

 his hand and encourage Ids heart in that course of 

 improvement which is most favourable both to his 

 physical comfort and his mental and moral develop- 

 ment, that it is impossible to avoid seeing that 

 li Herein is the finger or God : that here is wisdom 

 of plan and perfection of execution above all human 

 skiil and power above all human admiration." Such 

 are the wonderful displays of the wisdom and good- 

 ness of the Almighty Creator, which result from the 

 proper contemplation of his works, be the place, the 

 season, or the subject, what they may ; and it is these 

 which render the projwr study of natural history so 

 delightfully instrucihc, and make the abuse of it, by 

 trifling and narrow views, the most pernicious and 

 reprehensible of all idle dissipations. Hut, to return 

 to the great serpents by the margins of the waters in 

 tropical America. 



We have said, that as the intensity of the dry heat 

 increases, these animals become languid, and before 

 its close one may pass through the places of their 

 usual resort without the alarm-note of a single hiss 

 grating on the ear The brick-tinted earth, the 

 withered leaf, the dry reed, ready to take fire spon- 

 taneously, if the wind should rustle it before the rain 

 shall have drenched, are all silent in the stilly air and 

 under the burning agency of the sun ; and to a casual 

 observer, who sees the country only in this extreme 

 of one of its seasons, it appears as if Desolation had 

 set his seal there, never to be broken. 



But the Genius of the Andes looks down in pity 

 from his throne of eternal snows, amid roaring 

 volcanoes and rending earthquakes, upon those plains 

 all hastening to destruction. The air on the surface 

 of the ground is wonderfully transparent ; objects 

 which were not visible begin to come out, and sounds 

 are heard of which the ear could take no note only a 

 day bygone. The small quantity of water which 

 played between the earth and the nether air seems to 

 have floated upward, as it' the earth were about to be 

 deprived of even that unsatisfying draught, and the 

 wail of the exhausted cascade comes shrilly and 

 feebly through the forest, as if it were the prelude of 

 its soon being silent for ever. There is a white cloud 

 upon the distant hill, and the upper air is gummy ; 

 it looks as if all humidity were in motion upwards, 

 escaping to another region it may be to another 

 planet. As the sun declines, the white cloud blackens, 

 and the last rays of the sun stream in like molten 

 gold. But, unusual in such a climate at such a 

 season, not a drop of dew is formed, and thus the fear 

 is in part realised. As twilight fades, and iu those 

 latitudes it fades rapidly, the stars are surrounded 

 with haloes, and the southern cross resembles a 

 constellation of comets; but all arc soon lost in dark- 

 ness. Then the winds, which have hitherto been 

 more than usually still (for the dew of the evening 



