the Skeleton of Diplodocus Carnegiei. 365 



The Tail. 



The writer is convinced that no animal with such a tail as 

 Diplodocus possessed could possibly walk along on terra firma with 

 its huge body high above the ground and limbs erect, as in the 

 elephant. And yet such a fact is implied by the skeleton now 

 under consideration. By way of homely illustration, let us try to 

 picture a big Monitor lizard set up on stilts as it were, by giving it 

 long straight limbs, and made to walk with its heavy tail at such an 

 angle as this great Diplodocus tail makes with the hind-quarters. 

 Imagination fails ! The pull of such a mass of flesh as belongs to the 

 anterior caudal vertebrae would be prodigious ! These vertebras 

 would require to be greatly strengthened by ossified tendons, as in 

 Iguanodon. But even there the pull of the tail was lessened by the 

 comparative lightness of the vertebras. 



In all these matters the law of correlation is a useful guide, 

 though we admit by no means an infallible one. In a case like this 

 it seems quite reasonable to make use of this guide, as Cuvier did 

 who first propounded it. Looking at mammalian skeletons generally, 

 we seem to discover that big upright limbs and a proper quadrupedal 

 progression are correlated with small, light tails, as in ElepJias, Dos, 

 etc. Why is this? The answer seems to be, first, that the drag of 

 a heavy tail would be too great, and secondly, that the limbs are 

 designed for rapid movement. Let us inquire whether such a deduction 

 is confirmed by any extinct reptile. 



We return once more to the Dinosaur, which more than any other 

 approaches the heavy type of herbivorous mammals; and that is the 

 very remarkable Triceratops which bears out in a wonderful way 

 Cuvier's prophetic vision of a " great herbivorous reptile " as applied 

 to the famous Iguanodon. A glance at the model skeleton at South 

 Kensington with its huge hind-limbs shows that, instead of making 

 an angle with the body, they moved up and down in a vertical plane, 

 as in Elephas, Dos, etc., or a very nearly vertical one. So here we 

 actually have before us a reptile walking, as far as the hind-limbs 

 are concerned, after the manner of an ox ! Its toes point forwards ; 

 and it evidently walked in true quadrupedal fashion, though perhaps 

 they may have had a slight inclination outwards, as in birds. And 

 what about its tail? The tail is comparatively light and slender, and 

 quite unlike that of any other Dinosaur. And so our argument is 

 confirmed ; Diplodocus never had its femur working in a plane parallel 

 to axis of the body as in mammals. 



Discovert of a yet Greater Reptile. 

 Some five or six years ago, news was received of the discovery in 

 German East Africa of Dinosaurian bones, of the sub- order Sauropoda, 

 exceeding in length anything yet known even in the Western States. 

 Wonders never cease in the domain of palaeontology. Here were 

 bones of such colossal dimensions as would have fairly staggered 

 even the late Professor Marsh ! North America no longer can claim 

 the biggest reptile that ever walked the earth. East Africa takes 

 the palm. For here are bones which afford a basis of comparison of 

 relative sizes, and one authority has ventured to estimate the length 



