e Atlantosaur measures more than seventy inches, and the
femur of the Brachiosaur more than eighty. Many of these Deinosaurs must
have measured more than a hundred feet from the tip of the snout to the
end of the tail, and stood about thirty feet high from the ground. The
European Sauropods did not, apparently, reach the size of their American
cousins--so early did the inferiority of Europe begin--but our Ceteosaur
seems to have been about fifty feet long and ten feet in height.
Its thigh-bone was sixty-four inches long and twenty-seven inches in
circumference at the shaft. And in this order of reptiles, it must be
remembered, the bones are solid.

To complete the picture of the Sauropods, we must add that the whole
class is characterised by the extraordinary smallness of the brain.
The twenty-ton Brontosaur had a brain no larger than that of a new-born
human infant. Quite commonly the brain of one of these enormous animals
is no larger than a man's fist. It is true that, as far as the muscular
and sexual labour was concerned, the brain was supplemented by a great
enlargement of the spinal cord in the sacral region (at the top of the
thighs). This inferior "brain" was from ten to twenty times as large as
the brain in the skull. It would, however, be fully occupied with the
movement of the monstrous limbs and tail, and the sex-life, and does
not add in the least to the "mental" power of the Sauropods. They were
stupid, sluggish, unwieldy creatures, swollen parasites upon a luxuriant
vegetation, and we shall easily understand their disappearance at the
end of the Mesozoic Era, when the age of brawn will yield to an age of
brain.

The next order of the Deinosaurs is that of the biped vegetarians, the
Ornithopods, which gradually became heavily armoured and quadrupedal.
The familiar Iguanodon is the chief representative of this order in
Europe. Walking on its three-toed hind limbs, its head would be
fourteen or fifteen feet from the ground. The front part of its jaws was
toothless and covered with horn. It had, in fact, a kind of beak, and it
also approached the primitive bird in the structure of its pelvis and in
having five toes on its small front limbs. Some of the Ornithopods, such
as the Laosaur, were small (three or four feet in height) and
active, but many of the American specimens attained a great size. The
Camptosaur, which was closely related to the Iguanodon in structure, was
thirty feet from the snout to the en