STRUCTURE OF THE IGUANODON. 195 



a few connected caudal vertebrae, and two or three instances in which a femur, tibia, and fibula 

 and some metatarsals, were found in contiguity, all the bones were isolated. They have been 

 obtained from the quarries in St. Leonard's and Tilgate Forests, near Loxwood, Rusper, 

 Horsham, Cuckfield, and Battel ; and from the cliffs at Hastings, and in Sandown, and Brixton, 

 and Brook Bays, on the southern shore of the Isle of Wight. 



So anomalous is the osteology of the Iguanodon compared with that of existing saurians, that 

 from my discovery of the first vestige of this reptile —a fragment of a tooth — thirty years ago, 

 to the recent important acquisition of the jaws, I have had to contend with the opposition of 

 eminent naturalists, who have refused assent to the physiological inferences suggested by the 

 specimens which were from time to time brought to light, because the modifications of structure 

 in a colossal herbivorous reptile, essentially differed from the hypothetical archetype skeleton of the 

 class to wliich it belonged. When the first discovered teeth were shown to Baron Cuvier, he 

 pronounced them to he the incisors of a Rhinocei'os ; the metatarsals, those of a Hippopotamus ; 

 the fragment of a femur, with a medullaiy canal, that of some large mammalian. But the candour 

 and liberality of the founder of Paleentology were worthy of his transcendent genius ; upon 

 receiving further evidence, he immediately acknowledged the error, and expressed his conviction 

 that the teeth and bones belonged to an herbivorous reptile more extraordinary than any that had 

 previously been brought under his notice.' 



Even the lower jaw, which presents characters so peculiar as to admit, as I conceive, of but 

 one interpretation —that enunciated in my memoir on the teeth and jaws of the Iguanodon,^ — has 

 been adduced as affording a signal instance of the incorrectness of my physiological deductions. 

 And why ? Because in the entire class of living reptiles there is not a single species that has 

 cheeks and flexible lips, which, according to my view of the subject, the Iguanodon must have 

 possessed. But I do not hesitate to affirm that the structure and arrangement of the teeth, and 

 the mammalian character of the bones of the extremities, are in perfect accordance with my 

 exposition of the probable structure and functions of the maxillary organs of the original. The 

 naturalists who advance these objections, forget that among the existing mammalia there is one 

 genus, the Ornithorhynchus, or Duck-billed Platypus, that exhibits as striking a deviation from 

 the typical maxillary structure of its class, as does the Iguanodon. If before the discovery of 

 New Holland the jaw-bones of the Ornithorhynchus had been found in a fossil state in the strata 

 of Tilgate Forest, and I had ventured to infer that the oi'Iginal, though a true mammalian, and 

 giving suck to its young, had the extremities of the jaws covered with flat horny beaks, like 

 those of a duck, instead of with the fleshy lips and integuments which are the peculiar attributes 

 of its class, what censures would not my temerity have called forth ! We cannot too often be 

 reminded of the profound remark of William Penn : " Experience, which is continually contra- 

 dicting theory, is the only test of truth." 



The following are the physiological inferences relating to the structure and habits of the 

 Iguanodon, which Dr. Melville and myself conceive our investigations have established : the 



Organic Remains in the British Museum. All the Wealden reptilian remains of a large size, collected by me when residing 

 in Sussex, are in the upright glass cases in the same apartment. 



1 See Cuvier's Osaemeas Fossiles, tom. v. part. ii. It is much to be wished that those who aspire to emulate this great 

 man in scientific fame, would also endeavour to imitate him in the yet nobler attributes of his character. It is stated by 

 Professor Owen, in Brit. Assoc. Reports on Fossil Reptiles, that the bones of the Iguanodon were interpreted by me with the 

 aid of Cuvier and Clift. This is a mistake. Baron Cuvier died before I had obtained any considerable portion of the 

 skeleton ; and neither Mr. Clift nor Mr. Owen at that time could afford me any assistance in determining the natm-e of the 

 isolated bones I occasionally brought to the Hunterian Museum for comparison. Any aid I ever received in my investi- 

 gations is most fully acknowledged in my works. 



' See Philosophical Transactions, Part II. 1848. 



