habit; and may be compared to the movements of those oceanic fishes which, at certain seasons, seek the shoals near the shore, while they spend the rest of the year in deeper waters. “Take our shad as an example. It is caught on the coast of Georgia in February, on the Carolina shores a little later; in March it may be found in Washington and Baltimore, next in Philadelphia and New York; and it does not make its appearance in the Boston market (except when brought from farther south) before the latter part of April, or the beginning of May. This sequence has led to the belief that the shad migrates from Georgia to New England. An examination of the condition of these fishes, during the months when they are sold in our markets, shows at once that this cannot be the case. They are always full of roe, and, being valued for the table at this period, they are 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 successively 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 without being so, in fact.