63 



• KNOWLEDGE 



[Jan. 23, 1885. 



Everythiug, in fact, is strange in the iguanodon (Fig. .5). 

 Its stature, as well as its gait, is well calculated to astonish 

 the naturalist who is acquainted with existing reptiles ouly 

 — beings which are very puny as compared with animals 

 that lived in former times. 



The Btrnissart iguanolon measures nearly thirty-three 

 fe£t from the end of the nose to the tip of the tail, and, 

 when standing ujiright upon its hind legs (the attitude 

 that it assumed in walking), it rose to more th^n thirteen 

 feet above the level of the ground. The head is relatively 

 small and much compressed, and the nostrils are spacious 

 and as if partitioned. The temporal fossa is limited by a 

 bony arch, above as well as below — a chaiaoter entirely 

 exceptional in existing reptiles. The extremity of the 

 jaws were apparently provided with a beak designed 

 for cutting the large ferns and the cycadaceie that grew 

 upon the margins of the lagoons and mar-lies into which 

 the earth was cut up. The teeth, which are crenulate at 

 the edges, indicate an essentially herbivorous diet, and 

 they were replaced as soon as worn out. The nec-k must 

 have been very mobile. The ribs, which are strong, indi- 

 cate vast lungs. The fore limbs, shorter than the hind 

 ones, terminate iu a five fingered hand. The thumb is 

 provided with a large spur, which must have been a 

 formidable weapon. The hind limb, which is digifigrade, 



Tig. 5. — Skeleton of Ignanodon. 



is provided with but three fingers, which were probably 

 connected by a web. The pelvis more closely resembles 

 that of birds than that of existing reptiles. The tail, a 

 little longer than the rest of the body, is about sixteen 

 feet in length, and consists of nearly fifcy vertebrae. It is 

 much compressed laterally, like that of the crocodiles, and 

 mubt have served as a rapid and powerful means of pro- 

 pulsion. 



"The circums'ances under which the Bernissart iguano- 

 dons were fotind show, as Mr. Dupont has pointed out, 

 that these animals must have lived in the midst of marshes 

 and upon the banks of a river. It is consequently not 

 surprising that they had aquatic habits. 



'■ Granting that the iguanodons passed a portion of their 

 existence in water, we can imagine, by the aid of observa- 

 tions made upon the crocodile and amhbjrrhynrhu^ (a large 

 marine lizard of the Galapagos Islands), two very different 

 modes of progression of our dinosaur in the liquid element 



" When it was swimming slowly, it made use of its four 

 limbs and its tail. If, on the contrary, it wished to move 

 forward rapidly in order to escape its enemies, it placed its 

 fore limbs against its body, and made exclu>ive use of its 



hind ones and of its caudal appendage. In this mode of 

 progression, it is clear that the smaller the fore paws are 

 the more they are hidden, and consecjuently the less resis- 

 tance they offer to the movement of the animal in the water. 

 In confirmation of this, we observe that, among the forms 

 that swim in the manner just stated, the fore limbs are so 

 much the smaller in proportion as the beast is the more 

 aquatic. 



" The iguanodons walked on the ground by the aid of 

 their hind legs only ; in other words, they were bipeds after 

 the manner of man and of a large number of birds, and were 

 not jumpers like the kangaroo ; moreover, they did not 

 rest upon the tail, but allowed it simply to drag. 



" But, it will be said, just now in speaking of aquatic 

 life, you compared the iguanodon with the crocodiles ; yet 

 the latter are not adapted for an erect attitude. What neecf, 

 then, had the iguanodons of a bipedal walk if they had 

 analogous habits' It appears to us, on the contrary, that 

 standing upright must have been a great progress, and for 

 the following reason : 



" These animals, being herbivorous, had to serve as prey to 

 the carnivora of their epoch ; and, on another hand, they 

 remaineel in the midst of marshes. Among the fern^ by 

 which they were surrounded they would have observed the 

 approach of their enemies with difficulty, or not at all ; 

 but, standing upright, they were enabled to look about 

 them to a considerable distance. Upright, too, it was in 

 their power to seize their aggressor between their short, but 

 powerful arms, and to Vjury their two enormous spurs into 

 its body. These spur.«, it is probable, were provided with a 

 cutting edge. 



'• The difficult progression of the crocodile upon the 

 ground has been described by all travellers, and there can 

 be no doubt that the long tail of this animal con*ribute.s 

 not a little to its awkward gait. The transformation of 

 this cumbersome organ out of water into a balance was, it 

 seems to us, a happy modification. 



" Finally, the bipedal walk must certainly have allowett 

 the iguanodon to more quickly regain the river or lake in 

 which it disported than would a quadrupedal walk that 

 was continually interfered with by numerous aquatic plants- 

 that I'layed, after a manner, the lole of brushwocd.* — 

 Science tt 2^ ature. 



THE EEFORMATIOX IX 

 KEEPIXG.f 



By W. F. Allen. 



TBIE- 



ON Nov. 19, 1883, the daily papers of the United 

 States and Canada, from the Atlantic Ocean to the 

 Rocky Mountains, contained more or less elaborate accounts 

 of the change from local to "standard time" which hati 

 been made on the previous day. Comparatively few among 

 the millions of people whi read these accounts took the 

 trouble to investigate the actual meaning of the change or 

 the arguments in its favour. It appeared to be the work 

 of practical railway managers, and to be favoured by 

 leading scientists. Watchmakers agreed to and aided the 

 change, and few other persons were apparently interested. 

 So the people quietly acquiesced, reset their watches a few 

 minutes faster or .slower, and for the most part soon forgot 

 that any but " standard time '' had ever been in use. 



In the present generation we have become so accustomed 

 to the use of accurate time and the ready means of obtaining- 

 it, that we hardly realise how dependent we are upon it. 



* L. Dollo, Les Ifmanodons de Bernissart. 

 + From the Popular Science Monthly. 



