— 163 — .lOHS. souMijyr 



south of Ireland (48°04'N., 12°40'\V.)- one landed in Biiitany the other in the neigh- 

 bourhood of San Sebastian in Spain. 



To judge from the direction of these and the remainder of our bottles, from the di- 

 rection of the tioats put out by the Puinck oc Monaco further west in t;he Atlantic and 

 especially from those put out by the "Société d'Océanographie du Golfe de Gascogne" in 

 the southernmost part of the Bay of Biscay ', there can be no doubt that the surface cur- 

 rent in the Bay of Biscay flows in the main in a direction corresponding to the outline 

 of the coast (or curves of depth), thus from north-west to south-east. 



The same applies to the waters S.W. of Ireland- (that is, west of the large shallow 

 area with depths less than 200 meters S. of Ireland and W. of the English Channel). 

 Here also according to the investigations of the "Thor" the current flows mainly in an 

 south-easterly direction, following the outline of the slope of the coastal banks towards 

 the deep water of the Atlantic (see Charts I — ^VIII)-^ 



From what has been said, it is apparent that any drift of the pelagic fry from the 

 southern to the northern part of the Bay of Biscay is excluded. In our in- 

 vestigations also there is nothing which would indicate that such takes place; it seems 

 rather as if the opposite were the case. Thus Moreaü (1. c, p. 238) states for the occur- 

 rence of the haddock (G. ceglefinus) on the west coast of France: "assez commun jusqu'à 

 l'embouchure de la Gironde", though in spite of a favourable time of year (beginning of 

 May) we did not find a single specimen of the fry of the haddock anywhere in the Bay. 

 The most natural explanation of this seems to be that the haddock which occur so far to 

 the south came from northern waters. As will be seen from Chart III and the tables for 

 June 1906, fairly considerable quantities of large pelagic fry of the haddock were taken in 

 early summer over great depths S.W. of Ireland, thus just in the region where some of 

 our bottles which were carried in an south-easterly direction were thrown overboard. 

 These haddock must necessarily — like all other pelagic fry of fishes occurring out here — 

 be carried in a south-easterly direction in the course of the summer with the prevailing 

 currents. And I consider it very probable therefore, that the perhaps not quite inconsiderable 

 quantities mentioned by Moread which may occur in the Bay of Biscay, where the species 

 does not spawn according to our investigations, are due to the drift of the pelagic 

 fry produced in more northern waters (e. g. S. of Ireland)*, which is also quite 



' See Gh. Bbnard : Les Courants de l'Atlantique Nord et du Golfe de (Jascogne (Bulletin de géogra- 

 phie historique et descriptive, No. 2, Paris 1903) and "La Géographie", Tome XI, Paris 1905 (2me étude). 



- At least, for the parts which lie S. of ca. 50° N. L. 



3 Concerning the direction of the current inside the slope of the coastal banks (less than 200 meters 

 deep) S.W. and S.of L'eland, I am unable to say anything definitely, and I may therefore only state that 

 the pelagic fry which are either spawned beyond the slope of the coastal banks or like the haddock fry 

 mentioned above are carried out here from shallow water must drift in a south-easterly direction to- 

 wards the Bay of Biscay. 



•* There is indeed nothing surprising in this. We have already seen several examples of a species 

 occurring when not at the spawning time (e. g. in the adolescent stages) at quite different places from 

 were it spawns. Thus for example at Iceland, where several species are found on the E. and N. coasts 

 in quantities (e. g. haddock, cod, coalfish), though they do not spawn there owing to the low temperatures, 

 just because they are either carried there as pelagic fry by the oceanic currents or migrate there ac- 

 tively in the older stages. The difference between these waters and the Bay of Biscay is in this con- 

 nection only that, on the E. and N. of Iceland the temperatures are too low, in the Bay of Biscay too 

 high to permit of spawning, i. e. to permit of the occurrence of the fishes which are specially sensitive 



21* 



