But few bones of the feet, and especially the fore feet, are present, these smaller parts of the skeleton having been washed away before the ponderous frame was buried in the sand, and the best that can be done is to follow the law of probabilities and put three toes on the hind foot and five on the fore, two of these last without claws. The single blunt round claw among our bones shows, as do the teeth, that Triceratops was herbivorous; it also pointed a little downward, and this tells that in the living animal the sole of the foot was a thick, soft pad, somewhat as it is in the elephant and rhinoceros, and that the toes were not entirely free from one another. There are less than a dozen vertebrae and still fewer ribs, besides half a barrelful of pieces, from which to reconstruct a backbone twenty feet long. That the ribs are part from one side and part from another matters no more than it did in the case of the leg-bones; but the backbone presents a more difficult problem, since the pieces are not like so many checkers--all made after one pattern--but each has an individuality of its own. The total number of vertebrae must be guessed at (perhaps it would sound better to say estimated, but it really means the same), and knowing that some sections are from the front part of the vertebral column and some from the back, we must fill in the gaps as best we may. The ribs offer a little aid in this task, giving certain details of the vertebrae, while those in turn tell something about the adjoining parts of the ribs. We finish our Triceratops with a tail of moderate length, as indicated by the rapid taper of the few vertebrae available, and from these we gather, too, that in life the tail was round, and not flattened, and that it neither served for swimming nor for a balancing pole. And so, little by little, have been pieced together the fragments from which we have derived our knowledge of the past, and thus has the palaeontologist read the riddles of the rocks. [Illustration: Fig. 26.--Triceratops, He of the Three-horned Face. _From a statuette by Charles R. Knight._]