730 



HERON. 



of animal, as occurring in the two. In the central 

 parts of the eastern continent, drought is the prevail- 

 ing character of the climate ; and in America, on the 

 other hand, humidity predominates just as much. 

 Now, in order to ascertain whether we ought to ex- 

 pect any animal to thrive better, that is, to attain a 

 larger size and a more complete development, in the 

 one continent or in the other, we must attend to the 

 nature of the animal, so as to ascertain whether a dry 

 climate or a humid one is the more congenial to it. 

 If the former, we may presume that if the animal is 

 native in America as well as in the eastern continent, 

 it will be smaller and less perfectly developed in 

 America ; or if it is imported from the East to 

 America, it will degenerate. We have a remarkable 

 Instance, in the case of animals of the same family, in 

 the genus Felis, as existing in the two continents. 

 There is no question that the whole of that genus are 

 animals which prefer drought, and many of them can- 

 not bear a wet climate. Hence we do not find in any 

 part of America animals of such power and daring as 

 the lions and tigers of the East. 



But on the other hand, if the nature of the animal 

 adapts it more to a humid climate, we may expect to 

 find the same species more developed as native of 

 America than as native of the East ; or if imported 

 from the East into America, we may expect it to im- 

 prove. Here again we may take an illustration from 

 the mammalia of the two continents. Bears, from 

 their protecting coat of fat, and their strong and close 

 hair, which completely thatches them against the 

 weather, are remarkably well fitted for moist climates ; 

 and accordingly we meet with no land bears in the 

 eastern continent at all equal in size, in boldness, or 

 in strength, to those of America. 



Now, if we apply this theory, which is very obvi- 

 ously true, to the case of herons, which are found only 

 in marshy places, we can easily see that these birds 

 possess such natural advantages in the American 

 continent, as must lead us at once to conclude that the 

 same species must attain a larger size and a more 

 perfect development there. Food for herons, and 

 also trees adapted for their nesting-places, are vastly 

 more abundant in America than in the eastern conti- 

 nent, and therefore the birds have more enjoyment 

 and less labour. 



This is a point in the physiological geography of 

 animals, which, so far as we are aware, has not been [ 

 alluded to by any writer on the subject ; but it is ; 

 one of very great importance, not in helping us to ! 

 explain some climatal modifications of animals, which 

 otherwise would be a little perplexing, but as a warn- 

 ing against some very ridiculous prejudices which 

 have been taken up by the romancers in natural his- 

 tory ; and which, in consequence of the imposing 

 style in which they are stated, have gained no small 

 currency with the public. Taking up an exceedingly 

 partial view of the case, namely, that of one or two 

 animals, and not considering whether the climate of 

 the east or that of the west suited best with the nature 

 of those animals, these romancers of natural history 

 have come at once to this sweeping conclusion, that 

 " there is a tendency in nature to belittle all her 

 productions on the west side of the Atlantic." It was 

 somewhat natural that a sentence of condemnation so 

 sweeping as this should occasion some wrath on the 

 part of the American naturalists, though it does not 

 appear that they got more into the philosophy of the 

 case than their brsthren of the east ; and indeed, to 



speak about any tendency which nature has, either to 

 deteriorate or to improve her productions in one 

 country more than another, is to utter words which 

 have no meaning. That the whole system of nature, 

 in all its parts, is equally perfect, is the fundamental 

 truth ; and though we cannot in all cases draw a clear 

 line of distinction between that which determines a 

 natural character, and that which possesses the cha- 

 racter so determined, yet we may state it as perfectly 

 general, that, according as any place is, so will be its 

 productions ; and the very beauty of the earth, and 

 that which gives it its greatest value to man, as mak- 

 ing the different nations in so far dependent upon each 

 other, and thus pointing out to them the bonds of 

 general peace and reciprocal assistance, is the diver- 

 sity of climate and surface, and consequently of pro- 

 ductions, in the several countries and their several 

 districts. But, important as this point is, and necessary 

 as it is that it should be strongly inculcated, as ex- 

 tending much farther than mere matters of natural 

 history, we must leave it, and return to the little 

 white heron. 



Little Egret. 



The length of this species is about two feet, and 

 the extent of the wings between three and four ; the 

 weight rarely exceeds one pound. All the plumage 

 is of the most brilliant white ; the bird is furnished 

 with a pendent crest, formed of a few long, 

 straight, and waving feathers. There is a large tuft 

 of similar feathers on the lower part of the neck, 

 which are very straight and beautiful in their lustre. 

 From the top of the back there proceed three ranges 

 of feathers, about six or eight inches in length, with 

 slender shafts, and the webs thin and light, and in de- 

 tached filaments of a beautiful silky texture. The bill 

 is black ; the naked skin round the eyes greenish ; 

 the irides brilliant yellow ; the upper parts of the 

 tarsi, and the naked portion above the joint, greenish 

 black ; and the lower parts' of the tarsi and the toes 

 greenish yellow. The young want the produced 

 feathers on the neck and the back. In the first year 

 they are of a dull white, with the bill, the irides, and 

 all the naked skin black. They build in marshy 

 places, and the hatch consists of four or five white 

 eggs. 



Perhaps these are the most interesting birds of tht 



