160 



A JOURNEY IN BRAZIL. 



The Indians here are very skilful in fishing, and instead 

 of going to collect, Mr. Agassiz, immediately on arriving 

 at any station, sends off several fishermen of the place, 

 remaining himself on board to superintend the drawing 

 and putting up of the specimens as they arrive.* He 



* The opportunity of watching these fishes in their natural element, and 

 keeping many of them alive for hours or days in our glass tanks, was very 

 instructive, and suggested comparisons not dreamed of before. Our arrange- 

 ments were very convenient ; and as the commander of the steamer allowed me 

 to encumber the deck with all sorts of scientific apparatus, I had a number of 

 large glass dishes and wooden tubs in which I kept such specimens as I wished 

 to investigate with special care and to have drawn from life. One of the most 

 striking changes made by J. Miiller, in the classification of the spiny fishes, 

 was the separation into a distinct order, under the name of Pharyngognathi, 

 of all those in which the pharyngeal bones are soldered together. With these 

 the illustrious German anatomist has associated a number of soft-rayed types, 

 formerly united with the Pickerels and Herrings, and characterized by the same 

 structure. It would thus seem that there is here a definite anatomical character 

 easily traceable, by the aid of which a vast number of fishes might be correctly 

 classified. But the question at once arises. Are these fishes truly related to one 

 another, and so combined in this new order of Pharyngognathi as to include all 

 which properly belong with them, and none others 1 I think not. I believe that 

 Miiller has always placed too much value upon isolated anatomical characters ; 

 and, while he was undoubtedly one of the greatest anatomists and physiologists 

 of our age, he lacked zoological tact. This is especially evident with reference 

 to the order of Pharyngognathi, for though the Scomberesoces have fixed pha- 

 ryngeals like Chromides, Pomacentrides, Labroids, Holconotes, and Gerrides, 

 they have no real affinities with these families. Again, the character assigned 

 to this order is not constant even in the typical Pharyngognathi. I have found 

 Chromides and Gerrides with movable pharyngeals ; in the genus Cychla they 

 are normally so. It is therefore not out of place to state here that the Chro- 

 mides of South America are in reality closely related to a group of fishes very 

 generally found in the United States, known as Pomotis, Bryttus, Centrarchus, 

 etc., and usually referred to the family of Perches, from which they have, 

 however, been separated by Dr. Holbrook under the name of Helichthyoids. 

 They not only resemble the Chromides in their form, but even in their habits, 

 mode of reproduction, peculiar movements, and even in their coloration. 

 Cuvier has already shovm that Enoplosus is not a member of the family 



