14 A HISTORY OF THE WHALE FISHERIES 



The period of gestation is not known with any 

 certainty, but is generally supposed to be from ten 

 months to over a year. 



For the common Fin-whale (Balceno-piera 

 musculus, L.) it is supposed to be about eleven 

 months; for the Blue Whale (B. sibbaldi, Gray) 

 from eighteen to twenty months. 



Cetacea are generally gregarious, swimming in 

 " schools," formerly many thousands being met 

 together. They are timid, inoffensive animals, 

 Affectionate in their disposition, especially the 

 mother towards the young. 



All are predaceous, living on animal food. One 

 form alone, the Killer Whale or Grampus (Orca 

 gladiator), eats other warm-blooded forms, such as 

 seals. Some feed on fish, such as herring, others 

 on the plankton or drifting organisms of the surface 

 layers of sea water, such as small Crustacea, while 

 still others live on deep-sea cephalopods. In size 

 there is great variation, some of the smaller dolphins 

 scarcely exceeding four feet in length. The 

 question of size has an important bearing on the 

 future of the species, since whalers in the waters of 

 the British Islands find it does not pay to kill 

 Cetacea under forty feet in length. 



Cetacea formerly abounded in all known seas, 

 some species being also found in the larger rivers 

 of South America and Asia. 



Considerable information as to the species found 

 in British seas and their relative abundance has 

 recently been obtained from the Annual Reports of 



