Page:The Formation of Vegetable Mould through the Action of Worms (1881).djvu/221

 The section shown in Fig. 12 was taken in the centre of the Basilica, and though it was 5 feet in depth, the natural sub-soil was not

reached. The bed marked "concrete" was probably at one time a floor; and the beds beneath seem to be the remnants of more ancient buildings. The vegetable mould was