18993 We Go a-Fishi 



ng 



the foothills below Popocatepetl's eternal snows, Aipin, 

 from which one has a magnificent outlook down- ''-"''^'^'^ 

 ward as well as upward. But other things demand 

 attention, and I must not linger here. 



Leaving the party from time to time, Snyder and 

 I made several large collections — one at Lake 

 Chapala, famous as the choicest winter resort of 

 migratory birds on our continent, one at Puente de 

 Ixtla in a tributary of the Rio de las Balsas, and 

 one from the sea at Vera Cruz. Specially interest- a problem 

 ing is the fish fauna of the three volcanic lakes, '" 

 Chapala, Patzcuaro, and Zirahuen, as each separate '^-^°°^^ 

 body of water contains several species of closely 

 related, large atherine fishes or Silversides of the 

 genus Cbirostoma, all of very delicate flesh and 

 locally known as pescados hiancos, ** white fishes," 

 or pescados del rey, ''fishes of the king." Cbiros- 

 toma occurs only in various lakes of central Mexico, 

 though its allies are scattered over the warmer 

 parts of the world. But the singular feature is that 

 the dozen or so clearly defined species look very 

 much alike, forming an apparently marked devia- 

 tion from Jordan's Law.^ A probable explanation 

 of this anomaly is that earthquake disturbances at 

 one time or another threw together parts of different 

 river basins, thus mingling different faunas. 



In the hills of Xico near Jalapa, as already re- The 

 lated, I met my first coral snake, a venomous '"°''^^''''' 

 serpent of great beauty of color, which infests the 

 thickets of eastern Mexico. Its Sierran mimic, the 

 red-banded King Snake, a sworn enemy to the rattle- 

 snake, has the playful habit of winding suddenly, 



1 See Chapter xiv, page 329. 



c 643 :i 



