In active motion

Eliza BrightwenRambles with Nature Students, Londres, The Religious Tract Society, 1895, p. 223.

Returning from some other occupation. I found the small cases in active motion. A brown head and part of a white grub’s body appeared at one end, and each inseck, like the Caddis Worm, was dragging its house after it and seemed able to crawl rapidly about. By gently pressing the tail-end of a cocoon I made the grub come outand leave its case behind, so that I could examine it more particulary. The case was evidently made of shreds of the feathers on which the grub had been feding, andwas lined with fine white silk.