THE SUN-PERCH AND THE CATFISH 



the males, by a large scarlet-brown spot on a sort of 

 flap which prolongs the cheek backwards. It is really 

 beautiful, whether we watch it quivering when it has 

 just been taken from the water, or in a tank in some 

 aquarium. It is unfortunate that it has a flattish body 

 and poor flesh, that it never grows to any size, and 

 that the best specimens are scarcely larger than my 

 hand. Without these defects, it could only meet with 

 approval. 



" Anyhow, in becoming acclimatized, it has given 

 proof of a tenacity which indicates considerable strength. 

 It has become European, and takes its place among us 

 with an ease which its companion in origin, the black- 

 bass, never seemed to display. By itself, by its strength 

 alone, and given over to its own devices, it is progres- 

 sively extending its domain, enlarging it from affluent to 

 affluent, taking advantage of the flood waters, passing 

 through the canals, and finally reaching places where its 

 presence would never be suspected. It suddenly 

 appears in places where nobody ever put it. It colon- 

 izes by imperceptible means. Its advance is not 

 regular, for it does not always meet with the same 

 obstacles; it has its ups and downs; but, generally 

 speaking, it is continuous. Circumstances sometimes 

 favour and sometimes restrict it. Sometimes we find it 

 abounding and almost succeeding in chasing away the 

 other species, which is what has happened in our river ; 

 then, years afterwards, it goes off in numbers, and then 

 appears again. Although acclimatized, it is not yet so 

 much so that it is indifferent to external changes ; indeed 

 it seems excessively sensitive to them, much more so 

 than our native species, which have had a longer experi- 

 ence. According to the year, to the seasons and their 

 varying severity, spawning and the development of the 

 fry proceed differently, and the years that follow indicate 

 this by the numbers of the fish that appear. In one and 

 the same place the species succeed either to themselves 

 or to one another in accordance with these alternations. 



20I 



