Various concrements from the human body were investigated by metalloscopy, and their growing mechanism was studied. 1. The surface of forty choleliths, more than 50 uro-liths and 2 sialoliths were investigated by metalloscopy. A figure of spiral growth was seen in 9 uroliths, but neither in choleliths nor in sialoliths. 2. As above mentioned, there were a few caliculi, which developed by spiral growth mechanism, just like the usual crystal formation in the nature. These caliculi were consisted of uric acid mainly. 3. In uric acid caliculi at first the crystal granuli grow in spiral mechanism as elements and play a main roll for growth. In such way they need no strong colloidal chemical changes for their growth. 4. Other caliculi, in which no spiral growth figure has been found, are of course to have to had crystals as their main elements. Therefore it is considered that, they grow in the same spiral mechanism which could not only be found because of their desiccation after extirpation and insufficient magnification.