370 NATATORES. 



When the broods are reared, and the young fishes leave 

 the breeding grounds, the gannets disperse themselves over 

 the sea, rather than migrate. In the intermediate time, 

 before the smaller surface-fishes come near the shores for the 

 purpose of spawning, they are put a little to their shifts, and 

 they may be seen hovering over, and always now and then 

 driving down at, the shoals of cod, which cause a white 

 spray on the water where they are numerous ; but though 

 they wound a considerable number, by their powers, that 

 species of fishing, at least in the cases in which I have seen 

 it, does not appear to be very productive. Sprats and her- 

 rings suit better, especially when " taken in the set of the 

 current," as they are then captured by the birds while swim- 

 ming. We are not very well informed respecting the sea- 

 sonal economy of the surface of the sea ; but it is probable 

 that the fishes, and the surface fishes especially, have a south- 

 ward motion in the winter ; and that the gannets move sea- 

 ward and southward along with them, as we can hardly 

 suppose that birds, in which the colour and texture of the 

 plumage, as well as the quantity of air in the cellular tissue 

 under the skin, all conspire to resist changes of tempera- 

 ture, can have any occasion to shift southward on account of 

 the cold. Dispersion rather than departure seems to be the 

 chief cause why they are not seen in the winter. As they 

 float like balloons, they have less occasion to come on land, 

 except in the breeding time, than most other birds ; and 

 great as the numbers are which collect at their favourite 

 rocks in the summer, they would make but a sprinkling over 

 the sea to the distance of fifty or one hundred miles, and the 

 points of that wide surface which can be contemporaneously 

 viewed are exceedingly few. 



