346 A JOURNEY EN BRAZIL. 



brought to market at each locality until the spawning season 

 is over. Now, as they cannot breed twice within a few weeks, 

 it is evident that the shad which make their appearance suc- 

 cessively along the Atlantic coast from February to May are 

 not the same. It is the spring which migrates northward, 

 calling up the shoals of shad from the deeper sea, as it 

 touches in succession different points along the shore. 

 Such movements, if thus connected with the advancing 

 spring along a whole coast, appear to be migrations from 

 south to north, when they are, in fact, only the successive 

 rising of the same species from deeper to shallower waters 

 at the breeding season. In the same way it is probable that 

 the inequality in the seasons of rise and fall, between the 

 different tributaries of the Amazons and the various parts 

 of its own course, may give a sequence to the appearance of 

 the fish in certain localities, which seems like migration with- 

 out being so, in fact. 



" Keeping in view all the information I could obtain upon 

 this subject, I have attempted, wherever it was possible to 

 do so, to make collections simultaneously at different points 

 of the Amazons : thus, while I was collecting at Villa Bella 

 six months ago, some of my assistants were engaged in the 

 same way at Santarem, and higher up on the Tapajoz ; while 

 I was working at Teffe, parties were busy in the Hyavary, the 

 Iga, and the Hyutahy ; and during my last stay at Manaos, 

 parties have been collecting at Cudajas and at Manacaparu, 

 and higher up on the Rio Negro, as well as at some lower 

 points on the main river. At some of these stations I have 

 been able to repeat my investigations at different seasons, 

 though the intervals between the earlier and later collections 

 made at the same localities have, of course, not been the 

 same. Between the first collections made at Teffe and the 



