484 DEPARTMENT OF THE A^AYAL SERVICE 



show that more individuals were in the middle in the various channels, where Dawson 

 has shown that the water is comparatively stationary, than along the sides. Four of 

 the channel sections show this. 



The outflowing Cape Breton current depopulates the gulf to a considerable extent, 

 the older individuals being much less numerous during the second cruise. They are 

 carried by the current along the southern side of the Laurentian channel out into the 

 open Atlantic oil' the continental shelf for some distance and also into the deeper water 

 on the Breton bank. Such a course for the coastal water is indicated imperfectly by 

 Dickson's charts for surface temjjerature and salinity for the North Atlantic for the 

 years 1806 and 1897 (Phil. Trans., A, vol. 196, pis. 1-4, 1901), in which can be seen a 

 tongue of water of low salinity, warn in summer and autumn and cold in winter and 

 spring, extending along this course from Cabot strait. This is evidently a very per- 

 manent condition. The continuation of this tongue toward the southwest along the 

 outer side of the continental shelf, as appears, in fig-. 8 at Acadia station 12, may well 

 be a regular course for a part of the coastal water in the colder part of the year. It 

 will connect south of Sable island over the Scotian bank with the band of coastal water 

 along the JSTova Scotia shore. This view is supported by the finding of coastal water 

 at the bottom near La Have bank by the CJxallenger in May, 1873, and by the presence 

 of !S. elegans at Acadia station 54 (see fig. 10) which would be a last remmant for the 

 summer of this current. This cui-rent and the more constant one close to the Nova 

 Scotia coast carry the species to the southern end of Nova Scotia and heap it up there 

 as is seen in fig. 10. During the two months between cruises the currents have trans- 

 ferred the centre of abundance from the Laurentian channel to the lower end of Nova 

 Scotia, only a part being left on the Breton bank. 



The current along the southern coast of Newfoundland may carry coastal water 

 and with it this species to Cabot strait and possibly into the gulf. That it does not 

 enter to any great extent into the current running in past cape Ray will appear from 

 the following considerations. The stations in the northern half of the gulf during 

 both cruises showed few or no large 8. elegans. The cold intermediate water in which 

 it lives is present in this part of the gulf but will have been formed by the mixture of 

 the inflowing boreal water with the surface water, neither of which contain large 

 8. elegans. Consequently, few or no large individuals are to be expected in the first 

 part of the water's course, that is in the northern half of the gulf. If it were derived 

 from the coastal water south of Newfoundland, this would not be the case. 



The loss of large individuals from the gulf through Cabot strait being greater than 

 the gain, the gulf would be depopulated were it not for the yearly swarms of young 

 individuals growing up in the surface layers. These will likewise be carried out, but 

 since they are several times as numerous as the adults, enough will be left to keep up 

 the stock. The more or less stagnant areas in the gulf, for example the Bay of Islands 

 fjord, will aid in repopulating the whole area. The conditions in that fjord are most 

 suitable for this species. The bar at the mouth prevents the egress of the large 

 individuals during the summer at least and yet permits of many of the young escaping. 

 We found only the latter at the mouth in August. In the deepest haul in the bay, 

 where there was over 2O0 metres of suitable water, seventy large individuals were 

 obtained. This may be considered the upper limit for the number that is normal to 

 an area. More than this would certainly be due to concentration, as for example the 

 areas of abundance shown in figs. 8 and 10. The numerical relation between the 

 adults and young is interesting. At both stations in the Bay of Islands where vertical 

 hauls were made {No S3 stations 57 and 59) the young were about fifteen times as 

 numerous as the adults (^-%2 and ^''^%o). This provides a very considerable surplus 

 to overflow into the neighbouring depopulated part of the gulf. 



The areas of distribution of the boreal oceanic and northern coastal waters overlap 

 to a great extent. In the gulf of St. Lawrence where conditions are moderately static 

 they are separated vertically, the boreal water being below. Elsewhere the separation 

 is not so complete, more or less active vertical mixing going on, as is evidenced by the 



