alburnum

Darwin possesses the epidermis of poetry but not the cutis; the cortex without the liber, alburnum, lignum, or medulla.

This consists in cutting a ring round the tree with axes through the bark and sapwood, or alburnum, into the brown wood beneath.

It permits the passage of sap and is known as sapwood (Alburnum).

The mixture of bark and alburnum was next placed upon a smooth stone, and mashed into a fibre of a yellowish colour.