50 THE PROBLEMS OF THE DEEP SEA II 



and still more his remarkable paper " On the Geo- 

 logical Relations of the existing Fauna and Flora of 

 the British Isles," published in 1846, in the first 

 volume of the " Memoirs of the Geological Survey 

 of Great Britain," attracted universal attention. 



On the coasts of the British Islands, Forbes 

 distinguishes four zones or regions, the Littoral 

 (between tide marks), the Laminarian (between 

 lowwater-mark and 15 fathoms), the Coralline 

 (from 15 to 50 fathoms), and the Deep sea 

 or Coral region (from 50 fathoms to beyond 100 

 fathoms). But, in the deeper waters of the ^Egean 

 Sea, between the shore and a depth of 300 

 fathoms, Forbes was able to make out no fewer 

 than eight zones of life, in the course of which the 

 number and variety of forms gradually diminished ; 

 until, beyond 300 fathoms, life disappeared alto- 

 gether. Hence it appeared as if descent in the 

 sea had much the same effect on life, as ascent 

 on land. Recent investigations appear to show 

 that Forbes was right enough in his classification 

 of the facts of distribution in depth as they are to 

 be observed in the ^Egean ; and though, at the 

 time he wrote, one or two observations were 

 extant which might have warned him not to 

 generalize too extensively from his JEgean ex- 

 perience, his own dredging work was so much 

 more extensive and systematic than that of any 

 other naturalist, that it is not wonderful he should 

 have felt justified in building upon it. Never- 



