430 THE VARIOUS EXPLANATIONS. (‘The 10th. ] 
Cetacea for Fnaliosauria in our era, or the absence of remains of 
the latter in the tertiary deposits, is sufficient evidence of their 
non-existence im our seas; any more than the general replacement 
of Placoid and Ganoid fishes by the Cycloids and Ctenoids, or the 
absence of the former two from the tertiaries, is proof of their 
present non-existence.” 
“It must not be forgotten, as Mr. Darwin has ably insisted, 
that the specimens we possess of fossil organisms are very far in- 
deed from being a complete series. They are rather fragments acci- 
dentally preserved , by favouring circumstances, in an almost total 
wreck. The Analiosauria, particularly abundant in the secondary 
epoch, may have become sufficiently scarce in the tertiary to have 
no representative in these preserved fragmentary 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 vesicular 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 zoological sense. Would a Plesiosaurus float when dead? I 
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 war- 
rant for assuming that the Plesiosaur was encased in a thick blan- 
ket 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 abundant _ 
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 thousand 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 Hn- 
aliosaur and those of a Cetacean, we shall not, I think, attach 
great importance to this objection.” 
“The only region of the globe in which the unknown monster 
is reputed to be in any sense common, is the coast of Norway. 
