368 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY, 



against 80 hours in 1910). Unfortunately, there are no 

 data available from the Hebridean waters later than 

 August. There is a great want, as we have pointed out 

 before, of a series of periodic observations on the West 

 of Scotland, such as we now have year after year from 

 Port Erin in the Irish Sea. 



It seems unfortunate that the International Council 

 for the Investigation of the Sea has not included the 

 West Coast of Scotland in its scheme of work. It is 

 the only part of our outer coastal waters that has not 

 been systematically investigated. The West of Ireland 

 and the North of Scotland are included in the periodic 

 observations, and it is to be regretted that such an 

 interesting connecting link as the Hebridean Seas should 

 have been omitted from the official programme. 



We see no reason to modify our view that the spring 

 phyto-plankton seems to remain longer in northern 

 Scottish waters than it does in the Irish Sea. It 

 probably disappears more slowly some years than others, 

 and it certainly seems to be replaced more on some 

 occasions than on others by invasions of oceanic 

 zoo-plankton. This summer there seems to have been a 

 well-marked invasion of this character to the north of 

 Mull, carrying even such an Atlantic organism as 

 Doliolum almost into the Sound of Mull (see fig. 1). 



It seems not unlikely that there is a definite 

 connection between oceanic water containing Calanus in 

 quantity and shoals of herrings in the Hebrides. We 

 have noticed on several occasions that we obtained large 

 hauls of Calanus at spots where either the night before 

 or the night after good catches of herrings were reported. 

 This is one of several matters upon which we hope on 

 some future occasion to try to obtain more convincing 

 evidence. 



