14 LIFE IN THE SEA [OIL 



as a hake if pressed against it. But the pressures 

 in the abyssal regions are very much greater than 

 those which a hake has to withstand. Even the thermo- 

 meters at first used in deep-sea exploration were 

 frequently shattered to fine dust by the pressure of 

 the water ; and this is the great difficulty in the 

 construction of all instruments for the investigation 

 of the oceanic depths. 



Just as we recognise a littoral, a shallow water 

 and a deep-sea Benthos, so we may speak of an 

 Abyssal Benthos inhabiting the whole sea-bottom 

 deeper than 2000 fathoms. Before the time of the 

 great oceanographic expeditions there was much 

 speculation as to the nature of the animals which 

 might be found in the greatest depths of the sea. 

 It was thought that exploration might disclose 

 unfamiliar and bizarre forms of life, perhaps gigantic 

 animals, perhaps remnants of former geological faunas 

 persisting' under the uniform conditions of the abysses, 

 while all the rest of the earth was undergoing physical 

 change. These expectations have not been realised, 

 for all the animals captured from the deep belong to 

 well-known groups of life ; and with the exception 

 of some stalked Crinoids, animals closely allied to 

 the Crinoids which formed so characteristic a feature 

 of the fauna of the Carboniferous period, most of the 

 species belong to recently evolved groups. One 

 cannot say that there are no monstrous or gigantic 



