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LECTUBES ON BIOLOGY 



singly they would soon die from starvation, but Nature has 

 furnished them with a most ingenious straining-apparatus. The 

 mouth-cavity is of an enormous size ; from each side of the 

 upper jaw a double series of more than 200 horny plates hangs 

 down into the mouth. " Each plate is shaped like a sword or 

 scythe, reaching often a length of 5 metres. Both apex and 



FIG. 35. THE COMMON RORQUAL (Balcenoptera musculus). 



In the corner, head of embryo of Rorqual, with teeth of the upper jaw exposed, 

 also five single teeth. 



inner edge are frayed into hairy shreds. The mouth wide open, 

 the whale swims through shoals of pelagic animals. Having 

 secured a good mouthful, it closes its jaw, raises its tongue, 

 allows the water to strain out at the sides through the baleen 

 plates on the edge of which the food animals are caught ; thence 

 they are swallowed." 



