Edwin Lankester, An account of Askern and its mineral springs, Londres, John Churchill, 1842, p. 63.

The larvae of the various species of Phryganeae, called Caddis-worms, are exceedingly abundant in the ditches near Askern ; these insects, with their little cases, made of various materials, are sometimes so numerous as to make the bottom of  the water appear o moving mass.