REPRODUCTION 



363 



amnion, by far its largest part fills the 'sterile' horn where it forms part of 

 the placenta (Fig. 201). 



Since whales and dolphins cannot rear their young in caves or nests or 

 other sheltered spots, young whales must be able to surface for air, to 

 follow their mothers, and to keep warm (unlike dogs they cannot snuggle 

 up to their dam for comfort), the moment they are born. The only thing 

 their mother can do for them, is to feed them and, like the young of most 

 mammals, the Cetacean calf will begin to hunt for its mother's teat within 

 half an hour of its birth. Suckling apart, the young Cetacean is more or 

 less left to his own devices, and is born with fully open eyes, alert ears and 

 other senses, and enough muscle power to swim about quickly. All this 

 implies that, just like a calf or a foal, it must have fairly large dimensions 

 at birth. 



Thus a newdy-born Blue Whale is about twenty-five feet long, and may 

 w^eigh more than two tons (Fig. 202), and a newly-born Fin Whale may 

 measure twenty feet and has an average weight of over 4,000 lb. Grey 

 Whales measure fifteen feet at birth and weigh about 1,5001b. Newly- 

 born Sei, Humpback and Sperm Whales measure up to fifteen feet, 



'Jm 



Figure 202. Whales have gigantic calves. An 18-foot female foetus removed from a Blue 

 Whale carcass during the ig^y-ig^S season, on board the Willem Barendsz. 

 {Photograph: Dr W. Vervoort, Ley den.) 



