CAN any of your readers assist me in finding some artist who is really competent to produce, by any process which combines extreme accuracy with a reasonable cost, a large series of illustrations of variation in butterflies? The difficulty of getting such work done in the country under my own eye is very great, and I am unwilling to do as some of my friends advise, and get them made in Germany. Where the variation is a question of pattern only, photography would probably be the most satisfactory process; but where colour is the leading feature of the variation, chromo-lithography seems the most likely to succeed. The number of works on natural history which are privately published in England seems to point to a want of enterprise among English publishers which I cannot understand, as the market for really well illustrated works on ornithology, botany and entomology is certainly increasing. Any suggestions addressed to me will be gratefully received.