^92 CLASS AVES. 



tropics. This they preserve until the reapproach of the 

 season of reproduction, when they moult a second time, and 

 resume their brilliant colours. During both moultings, how- 

 ever, they are found more or less variegated with the colours 

 peculiar to themselves, according as they are more or less 

 advanced in each moulting. From this change of colour, 

 twice a year, from the variegation during the two moultings, 

 from the difference of the sexes, and the young, it has hap- 

 pened that many more species have been described than in 

 reality existed. For a proper determination they should be 

 studied in their living state, as M. Levaillant has studied 

 them, though unfortunately but a small number has come 

 under the inspection of that eminent naturalist. It is, there- 

 fore, more than probable, that many will be found in our 

 additions to the text, which are merely nominal. 



The souimangas live on insects, to which they add the 

 melliferous juice of flowers. This has been denied by some 

 naturalists, who have declared that they could not do so, as 

 their tongue is unfitted for the purpose : an assertion which 

 only proves that such naturalists never beheld the tongue 

 in question. It is conformed exactly like that of the hum- 

 ming-birds, who live precisely in the same manner. " The 

 parietes of this tongue," says M. Levaillant, " are of a 

 substance which is corneous, and hollowed into a 

 gutter, forming a sort of proboscis, the extremity of 

 which is provided with many nervous threads, which, by 

 their nature, constitute the first seat of taste. These 

 threads serve not only to taste the liquor, but also, as a 

 kind of sieve, to prevent grosser materials from passing along 

 with the saccharine juice through the tube of the tongue, 

 which they would thus obstruct. The hinder part of the 

 tongue, which corresponds to the oesophagus, is furnished 

 with two elongations, which, passing on each side of the 

 larynx, proceed behind the head to implant themselves in the 

 forehead, and serve, as with the woodpeckers, to push the 



