Those who, like Professor Pigorini, are acquainted with the structural features of the terremare of Northern Italy, will not be surprised at the comparative rarity with which piles are met with in the _terpen_, because of the rapidity with which timbers, when buried in dry earth, decay and disappear altogether, leaving in many instances no traces whatever behind them. This fact was strikingly shown by Chierici, who produced positive evidence of the former existence of piles in the upper strata of some of the terremare, by showing that the holes left by the piles, after the woody fibre had completely disappeared by decomposition, had become subsequently filled up by dust and infiltrated material, which ultimately became hardened, and so retained the actual form of the original piles. (See page 248.) In short, natural casts of the original piles were accidentally formed, which thus disclosed a knowledge of their former existence, which otherwise might never have been suspected. To the soundness of this deduction I have myself unconsciously contributed by an observation which I made some years ago, while digging at the crannog of Lochspouts, and having recorded it I may perhaps be allowed here to repeat my words. "One day I was greatly puzzled by finding what was evidently a portion of a birch tree, from 6 to 9 inches in diameter, quite flat, and with scarcely any wood left inside the thick bark. In no instance previously had I seen the evidence of pressure on logs of this size; but after carefully considering the point it was ascertained that such effects occurred only in the upper portion of the mound, and above the log pavement, where the wood had been exposed to atmospheric influences, so that when the woody fibres rotted away the flattening of the bark was easily produced. All the logs found buried in water or mud retained their original dimensions and showed no trace of having yielded to superincumbent pressure."[66] The absence of piles and wooden structures from many of these mounds is, therefore, no proof that they have not formerly existed; and, indeed, it is difficult to account for the horizontality and regularity of the beds on any other hypothesis. While I wandered about amidst the various sections presented by the progressive stages of the excavations, wondering at the distinctness of the strata, or picking up stray objects from the _débris_, such as mussel shells, bits of bone, fragments of pottery, etc., which were to be found here and there sticking in the face of the cuttings, my friend, Mr. Battaerd, was deeply occupied in examining a heap of bones, which lay weathering in a sunny corner. Having joined him in his osteological study, I found that the chief point of attraction was the head of a urus (_Bos_ _primigenius_) of great size, and with splendid horn cores--the finest example, according to Mr. Battaerd, that had yet found its way to the museum.