THE GREAT UNKNOWN. 



have no representative in these preserved fragmen- 

 tary collections, and yet not have been absolutely 

 extinct.* 



But Professor Owen presses also the absence of 

 any recognised recent remains of such animals. 

 Let us test this evidence first by hypothesis, and 

 then by actual fact. 



It may be that a true serpent, with large vesi- 

 cular lungs, would float when dead, and be liable 

 to be seen by navigators in that condition, or to 

 be washed ashore, where its peculiar skeleton 

 would be sure to attract notice. But, as I have 

 before said, I do not by any means believe that 

 the unknown creature is a serpent in the zoologi- 

 cal sense. Would a Piemoanurna float when dead? 

 1 think not. It is supposed to have had affinities 

 with the whales. Now, a whale sinks like lead as 

 soon as the blubber is removed ; the surface-fat 

 alone causes a whale to float. But we have no 

 warrant for assuming that the Plesiosaur was 

 encased in a thick blanket of blubber ; no geologist 

 has suggested any such thing, and the long neck 

 forbids it; and if not, doubtless it would sink, and 

 not float, when dead. Therefore the stranding of 

 such a carcase, or the washing ashore of such a 

 skeleton, would most probably be an extremely 

 rare occurrence, even if the animal were as abun- 

 dant as the sperm-whale ; but, on the supposition 

 that the species itself is almost extinct, we ought 

 not to expect such an incident, perhaps, in a thou- 

 sand years. If we add to this the recollection, 

 how small a portion of the border of the ocean is 

 habitually viewed by persons able to discriminate 

 between the vertebrae of an Enalicsaur and those 



* I reason as a geologist, on geological premises,— reserving 

 my own convictions on the subject of prochronism, which 

 would not affect this argument. 

 341 



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