162 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 
Mr. Holt’s figures* show that spring maxima of the 
salinities are only found at stations situated to the East 
of a line running W.S.W. from the Calf of Man to latitude 
03° 38’ N. and thence approximately S.S.W. It is there- 
fore permissible to conclude from our results, in conjunc- 
tion with Mr. Holt’s, that there is a narrow tongue of Gulf 
Stream water running up the centre of the Irish Sea, the 
effect of which on the salinity can be detected as far as a 
little to the Hast of the lne Calf of Man—Ttolyhead. 
Owing to the fact that the tide from the South is stronger 
than that from the North, the water composing this 
tongue eventually passes right through the Irish Sea and 
out through the North Channel, but beyond the point 
mentioned its effects are masked. The salinity results, 
moreover, bring out another very important point, and 
that is that nearly all this water passes to the Hast of the 
Isle of Man, only a relatively unimportant part running 
round to the West of the Island. Of course, one already 
knew that this was probably the case from the general 
set of the tides in this area. | 
It must be remembered that the strength of the Gulf 
Stream Drift varies from year to year, so that its effect 
will be more marked in the Irish Sea in some years than 
in others. During 1906 and 1907, for example, it does 
not appear to have been quite so strong as in 1908, for in 
the former we only found maximum salinities im the 
spring at the two Stations V and VI, while in 1908 we 
have found spring maxima at the three Stations V, VI 
and VII. 
It is worth noting that the course followed by the 
Gulf Stream Drift up the Irish Sea bears no relation to 
the deep channel which runs between Ireland and the Isle 
of Man and through the North Channel. As is well 
* Not yet published, but very kindly communicated to us. 
EE eee 
