A relatively undifferentiated cell in an epithelial sheet that forms more specialized cells.

Small cells found at the bottom of the epidermis, the outer layer of the skin.

Cells, which are in the deepest layer of the skin (epidermis). All new skin cells develop from these cells.

Basal region of the forewing that is enclosed anteriorly by the submarginal vein, posteriorly by the cubital fold or cubital setal line, if present, and depending on the setal pattern either the basal fold or basal setal line or linea calva apically. [drawing

substructure

structure