ADVENTURES OF A YOUNG NATURALIST. 225 



covered with verdure. In a hundred paces more, we reached 

 some pyramid-shaped rocks, which were bound together by the 

 gigantic roots of a tree with scanty foliage. The water glided 

 noiselessly through the stones, and disappeared under a low arch 

 shaded by gladiolas, covered with blossoms. 



Lucien, who was leaning over the opening, wanted to know 

 what became of the water. 



" Perhaps it is absorbed by sand underneath, perhaps it will 

 reappear in the valleys, where the surface sinks to its level," I 

 answered. 



" Do streams often go under the ground like tins'?" 



".Yes ; particularly in Mexico, where these subterranean pass- 

 ages are numerous. Near Chiquihuita, about five leagues from 

 the road which leads to Vera Cruz and Cordova, a large river 

 vanishes into a cave, which is more than three miles in length.'' 



" Oh ! how I should like to' see such a large grotto." 



" Your wish shall be gratified, provided we do not lose our 

 way in the Terre-Chaude.'" 



Sumichrast had only a few minutes left us, when we heard a 

 report, and he reappeared carrying a magnificent bird, whose red 

 plumage had a purple metallic lustre. 



" We have never met with this fine fellow before," said Lucien. 



" It is the most brilliant of all the American passerines," I 

 replied — " the Ampelis pompadora ; but its splendid attire lasts 

 only for a very short time. In a few days, its bright-coloured 

 feathers fall off, and are replaced by a sombre, dull-looking coat. 

 This moulting, which is common to many birds, has more than 

 once led ornithologists into error, who have described, as a new 

 species, a bird which a new dress has prevented them from recog- 

 nising. 



The neighbourhood of the sumidero furnished us with a dozen 

 birds of different species • among others, several tanagers peculiar 

 to America, and a pair of pretty light-brown cuckoos, with fan- 

 shaped tails, which are merely birds of passage in this locality. 



" When you are speaking of a bird, why do you often say it 



belongs to Brazil, Guiana, or Peru, when you actually find it in 



Mexico 1 " asked Lucien. 



p 



