286 SALMON AND TROUT. 



matter whence their name of ' faggot insects ' is derived. The 

 maggot-like larvse form for themselves cases for shelter or 

 security in which they dwell for many months before they quit 

 the water and take the air as flies. They carry their wings 

 when crawling which they do much more freely than the 

 Ephemera not raised in pairs above the thorax, but folded 

 pent-house fashion above the abdomen. The larvae are com- 

 monly known as ' caddis ' or case worms, and the abodes they 

 construct for themselves, partly by the use of their strong 

 nippers and partly by the aid of some natural glue furnished 

 by their own bodies, exhibit a curious and interesting variety. 

 These ' cases ' ascend by a graduated scale from the simplest 

 to the most complicated forms. First we have an inch of 

 slender rush ; then a more solid tenement formed from a piece 

 of stick, in which the grub takes the place of the pith ; then 

 two leaves gummed together at the edges. Anon we find a 

 fasciculus of tiny twigs, or a small clustered pillar of rush-rods, 

 cut accurately to one length and curiously joined together. 

 The most beautiful of all are cylindrical grottos, sometimes 

 nearly two inches in length, formed of small fresh-water shells. 

 A studious entomologist who was also a fly fisher might do 

 worse than to make a collection of these ingenious dwellings 

 and figure the ' imago ' hatched from each. It would, I presume, 

 be found that each class of dwelling belongs to a different 

 species. I have found many kinds together in one spring 

 ditch or sedgy backwater, so that there must have been a choice 

 of material, though I cannot affirm that when I have dislodged 

 the inmates for bait I have noticed any marked differences but 

 those of size and colour. 



It would be a curious experiment to transport a large 

 number, say of the rush worms, to a stream where they would 

 find no rushes, and then to observe whether, after the flies had 

 hatched and bred, their progeny would disappear or would 

 protect themselves by adopting some new building material. 



But I am digressing. Let me return to my fly book, and 

 say that the artificial flies representing the PJiryganea, have 



