220 WHALES AND DOLPHINS 



fleshy development of the lower lips found in Balcena, and 

 associated in that whale with the much longer baleen plates 

 and arched fore part of the skull, are not found in the Blue 

 Whale. The baleen in the Blue Whale is jet black, and the 

 hairy fringes are the same colour. 



Hairs are to be found on the tip of the lower jaw, along the 

 side of each jaw and on the surface of the rostrum, but this 

 typical mammalian covering is here reduced as in other whales, 

 almost to disappearing point. The " beard " consists of 20 

 to 40 hairs, the number on jaws and rostrum being anything 

 between 2 and 20 on each side. 



The colour of this species is conveyed by its name ; it is a 

 dark slate blue over the whole of the body with the exception 

 of the tip and under surface of the flippers, where pigmentation 

 is absent. The actual shade of blue may vary quite con- 

 siderably in different individuals, and may be modified by 

 a pale mottling which is sometimes diffused and sometimes 

 concentrated in coalesced patches in different regions of the 

 body. 



The dorsal fin is particularly low and small and placed far 

 back on the body ; the flippers are long and tapering, measuring 

 about one-seventh of the total body-length, and have a convex 

 lower border. The ventral grooves on the throat and chest 

 region vary in number, but 80 to 100 are generally present. 



The fully-grown Blue Whale may reach a length of 100 feet, 

 and records of specimens over 90 feet long are quite common. 

 At birth this animal is over 24 feet in length — an astonishing 

 size when we consider that only about a year is required for 

 this growth and development to be accomplished. Two Blue 

 Whales weighed piece by piece at a South Georgia whaling 

 station gave the following results : the one, 89 feet long, 

 weighed over iiq tons ; the other, 66 feet long, 51 tons. 

 These figures approximate very roughly to the weight 

 estimations of Blue and Fin Whales made by the whalers, 

 allowing a ton for each foot of length. 



It has already been stated that the distribution of the Blue 

 Whale is world wide ; it has been the object of commercial 

 pursuit almost since the inception of modern whaling in the 

 middle of last century. In the last period for which figures 

 are available, the southern summer season, 1934-35, and the 



