ダーウィン『種の起源』 (1959)の12章に、実にダーウィンの人柄を感じさせるこういう話がある。 I took in February three table-spoonfuls of mud from three different points, beneath water, on the edge of a little pond; this mud when dry weighed only 6¾ ounces; I kept it covered up in my study for six months, pulling up and counting each plant as it grew; the plants were of many kinds, and were altogether 537 in number; and yet the viscid mud w