The cotton fibres represent epidermal prolongations of seed coat cells. A raw cotton fibre, on average, gives the following values on analysis : cellulose, $94 \%$, protein - $1.3 \%$, pectic substances $-0.9 \%$, ash $-1.2 \%$, wax $-0.6 \%$, sugars $-0.3 \%$ and traces of pigments and mineral matter.