VBiit On the Foot-marks of Animals in Rocks. 



from the other divisions of the foot are plantigrade; and in this 

 instance, not the slightest vestige of a tarsus is visible, even in 

 places where the animal appears to have slipped. The batra- 

 cians have very frequently the thumb remote from the other 

 divisions, without any conspicuous tarsus, and the anterior feet 

 are sometimes much smaller than the hinder ones. Salamanders 

 walk with an amble, and if none of the batracians walk en 

 Jauchantj that mode of progression is exemplified in cameleons, 

 not only on trees, but likewise on land. Such are the reasons 

 which have led me to believe, that the animals in question 

 were either batracians or gigantic saurians. 



No one who has examined these marks, particularly in situ, 

 will ever conceive them to be concretions or lusus naturce, which 

 might have imposed upon naturalists. The toes often well cha- 

 racterized by the appearance of the joints — the anterior feet al- 

 ways smaller than the hinder ones — the thumb remote from the 

 other fingers, directed sometimes to one side, sometimes to ano- 

 ther, according to an invariable rule — and all these appearances 

 found alike in four quarries considerably distant from each 

 other, render it impossible that these impressions could be pro- 

 duced by chance. 



But there are other impressions on the same stone of a more 

 doubtful character. One frequently meets with a net of large 

 quadrangular meshes of rounded threads, the projection of which 

 above the surface of the stone is about half an inch. Naturalists 

 have regarded these as crevices which have been filled with sand, 

 in the same manner as the foot-prints. The regularity of the 

 meshes, however, the nearly straight threads of the net, and the 

 almost uniform thickness of these threads, do not conform to 

 the idea of rents or crevices. They may be compared to roots, 

 or rather rhizomes, such as those of the Acorus calamus, which 

 creep on the surface of marshes, which, when decayed, would 

 leave marks which would subsequently become filled with sand. 

 But it has been objected that those roots do not present true 

 anastomoses, such as are observed in this net -work. This is 

 true ; but I lately saw the roots of a Taxus in the botanical 

 gallery of the Museum of Natural History, the branches of 

 which are naturally grafted into each other, in such a manner as 



