Sept. 6, 1883] 



NATURE 



441 



relative positions, and the humerus whh its head still 

 within the glenoid cavity. The circumstance that in the 

 case of these Bernissart skeletons the bones are so largely 

 preserved in their immediate natural relations adds 

 immensely to their importance, for the position of every 

 bone can be determined with certainty. The nearest 

 approach to the peculiar structure of the sternum in 

 Iguanodon appears to M. Dollo to be that existing in 

 some young birds, especially in Vanellus cristatus as 

 figured by Parker. Professor Marsh regarded the 

 supposed presence of clavicles in Iguanodon as an 

 important point in them of resemblance to birds ; the 

 point must now drop, but there are abundance of others 

 in the Iguanodon skeleton in which the remarkable 



resemblances between the Ornithopoda and birds, pointed 

 out by Professor Huxley with such surpassing sagacity 

 more than t welve years ago, are borne out in a most remark- 

 able manner. Professor Huxley had very imperfect 

 material to guide him in his ideal restoration of the 

 Iguanodon skeleton, and it is wonderful in how few 

 matters of detail his results need correction now that one 

 can stand at Brussels with a perfectly complete skeleton 

 of Iguanodon towering over one's head, and test his 

 results with as it were a complete solution of the puzzle 

 at command. First of all there seems to be little doubt 

 possible that the Iguanodons walked, as be pointed out, 

 on their hind limbs erect like birds, in somewhat the 

 attitude shown in the accompanying figure. Several 



Iguanodon Bernissartcnsis, B'gr. At the Brussels Royal Museum of Natural History. Restored and mounted by M. L. F. De Pauw. Head, a, left 

 nostril; 0, left orbit; c. left temporal fossa. Vertebral column, d. cervical region; c, dorso-lumbar region; /, sacral region; £\ caudal region; 

 h, left scapula ; :'. left coracoid: k, left humerus; /, left ulna ; in, left radius : n, sternum ; o, left ilium ; /, left pubis ; q, left post-pubis ; r, 

 left ischium ; s, left femur; t, left tibia ; w, left fibula ; z\ third (fourth) trochanter. I, II, III, IV, V, digits. -\", diagrammatic transverse section of the 

 body between the fore and hind limbs. 



different lines of evidence, as M. Dollo points out, tend to 

 prove this. Firstly the remarkable resemblances between 

 the structure of the pelvis and the posterior limbs of 

 birds and the corresponding parts in the Iguanodons. 

 The points of resemblance of the ilium and ischium, 

 pointed out by Professor Huxley, are fully confirmed by 

 the Bernissart specimens ; with regard to the pubis 

 Huxley only recognised a part in Iguanodon, the post- 

 pubis ; and Hulke was the first to give a nearly correct 

 figure of the whole. The actual pubis is very large in 

 Iguanodon, as will be seen in the figure, and projects 

 forwards and outwards, forming an obtuse angle with 

 the post-pubis. Mr. Hulke was therefore not quite 

 correct in his conclusions as to its attitude, and there is 

 no symphysis pubis present ; the post-pubis is long and 

 slender, and directed backwards alongside the ischium, as 



in birds, for a considerable distance beyond the ischial 

 tuberosity. It is not incomplete, as supposed by Marsh 

 (from the examination of drawings of Bernissart specimens 

 in which it was imperfect). M. Dollo is inclined to 

 follow Professor Marsh in identifying the Dinosaurian 

 pubis with the pectineal process of the pelvis of birds, 

 a conclusion which receives most interesting support in 

 the valuable memoir lately published by Miss Alice 

 Johnson of Cambridge on " The Development of the 

 Pelvic Girdle in the Chick," l in which it is shown 

 that in the embryo fowl the cartilaginous representative 

 of the pectineal process is at first much larger and 

 more prominent in proportion to the dimensions of the 

 pelvis than subsequently, and becomes gradually reduced 

 as development proceeds. The peculiar form of the 



1 Quarterly Journal Microscopical Science, July, 1883. 



