"This is the Dry Fly Entomology, 1897, completely rewritten and very greatly improved; the first serious attempt to represent the natural insects found on the water" (Callahan & Morgan). Contrary to what Halford says in Floating Flies and How to Dress Them (1886) and Dry Fly Entomology (1897) where 90 and 100 flies are described, in Modern Development he now feels that the 33 "are, to my mind, quite sufficient patterns for any dry-fly man on a south country or other chalk stream." During 1902 Halford collected a very large number of specimens of flies on which the rising trout were feeding and preserved them in formalin which he had read about in an article in the Field in 1901. He then worked out the new patterns with the local fly-dresser reproducing as nearly as possible the precise shades of colour of the natural insect. He fished with these flies only from 1903 to 1909 with great success. Part I - The Halford Dry Fly Patterns - contains everything concerned with tying these patterns, matching the colours, sizes, proportions, tools and materials required etc. Part II -The Halford Dry Fly Patterns in Use - is just that but, of course, with Halford's inimitable attention to detail and analysis. This Flyfisher's Classic Library edition was limited to 150 numbered copies [though this copy is not numbered] and includes a new fourteen-page introduction by Tony Hayter.