No. 521] 



SAUBOPOD DINOSAURS 



277 



Verankerungsmittel." No doubt it did to a certain ex- 

 tent so function, but to regard it as having been an in- 

 strument for promoting, as Sternfeld indicates, a wrig- 

 gling motion— " schlangelnde Bewegung"— is to attribute 

 to the organ properties which it hardly possessed. The 

 tail, while capable, no doubt, when the animal assumed 

 a crouching position, of functioning as Tornier demands 

 that it shall, must nevertheless have been to a very large 

 degree used also as a support upon which the animal 

 could when necessary prop itself, as upon one of the 

 legs of a tripod, as undoubtedly was the case with the 

 carnivorous dinosaurs, to which the sauropoda are not 

 so very distantly related. 



The theory, which has been proposed by Dr. Hay, that 

 it was impossible for these huge sauropods to rear up- 

 ward, seems to me to be one that any one who has care- 

 fully studied the movements of animals, and especially of 

 reptiles (turtles excepted), must repudiate. We know that 

 certain of the smaller lacertilia to-day, when in rapid mo- 

 tion, assume a bipedal pose. Professor Oshorn in one of 

 his papers has given us a reproduction of the figure of 

 ( 'hliuiiiiflosaurus in a running attitude, taken from an 

 instantaneous photograph by Saville-Kent (Fig. 18). 



Even more striking than the posture shown in this pic- 

 ture is the position constantly assumed by a well-known 

 lizard of our southwestern and western country, Crota- 

 phytus collaris Say. I regret that although I have had 

 a number of these animals in captivity at our museum 

 I never took the pains to have photographic snap-shots 

 made of them when rapidly running across the floor. 

 They assume when so doing a position in which the body 



