I have always paid great attention to natural forms, such as bones, shells, and pebbles, etc. Sometimes for several years running I have been to the same part of the seashore – but each year a new shape of pebble has caught my eye, which the year before, though it was there in hundreds, I never saw... Pebbles show Nature's way of working stone. Some of the pebbles I pick up have holes right through them... A piece of stone can have [for the sculptor] a hole through it and not be weakened – if the hole is of a studied size, shape and direction. On the principle of the arch, it can remain just as strong.