In British New Guinea similar tactics are resorted to by the native doctors. A native who was suffering from lumbago fully believed the tale that his disease was caused by a stone embedded in his flesh. When the sorcerer made passes over this man’s back and then exhibited a stone which he pretended to have taken thence, the sufferer was convinced that the disease had left his body, and he began to feel relief. When examined, his back showed some superficial cuts at the spot where the stone was said to have been extracted. In another case, however, when a child was to be operated upon in a like way, the child’s father became suspicious and seized the operator’s hands before they came into contact with the little one’s body; the result being that the disease-laden stone was found concealed in the operator’s hand.[34] Pebble-mania or lithomania is an inherent trait in all mankind. From the most primitive man to the most modern, especially those of optimistic and investigating tendencies, this trait is present in a greater or lesser degree. That is, curious people would collect pebbles for their bright colors, or markings, for their transparency or translucence, and those of an investigating turn of mind, under the impression that the find was perhaps a diamond or a gem of some kind. In modern times this kind of collecting has developed into a regular industry, pebbles found on the shores of the United States and which are either pure white, transparent or translucent quartz, being cut and offered for sale. These pebbles are gathered, and are valuable to those who make a business of selling them, because the white opaque pebbles become translucent after cutting, or rather, during the process of cutting, and they are then passed off for moonstones, which are worth from one-third to one-half more than the cost of cutting the quartz pebbles, the purchaser being led to believe that he is getting a moonstone, although this could not be possible, since moonstones have never been found on either the eastern or the western coast of the United States. As for the cut moonstones which are brought back by the tourist, under the impression that he is getting native material and workmanship, these all come from Europe. Pebble-mania is not confined to mankind alone. Birds and animals possess it. The magpie picks up and hides away bright objects, including odd pebbles, or carries them to its nest. The stones known as _ætites_ were said to be found in eagles’ nests, although they may have been swallowed by the birds for digestive purposes, just as the hen’s crop is full of stones, many of them being transparent, a proof that the fowl had been attracted by them, and had swallowed these in preference to other, duller ones. Notable instances of transparent pebbles are the _alectorii_, or “cock-stones.”