The curious little gravel-houses

Laura Winthrop Johnson, « Eight Hundred Miles in an Ambulance »,Philadelphie,  Lippincott’s Magazine of Popular Literature and Science,  vol. XVI, 1875, p. 68.

We rambled about; bathed in the clear stream, where we found numbers of the curious little gravel-houses of the caddis-worm ; and napped away part of the long afternoon.