ARNOLD ARBORETUM HARVARD.UNIVERSITYJamaica Plain, Mass, February 13, 1900My dear Muir:I am delighted to get your letter of the 21st. Your letters always oheer and inspire me and I wish I could get more of them. I wish, too, I could go to California this summer and see the Redwoods again hut I must stay at home and do some hard work between now and the middle of September when I suppose I must start forth again to hunt for Crataegus. I shall certainly be able to throw a good deal of light on the genus before I get done with it but it is giving me a lot of bother and anxiety. Still I suppose I might as well do that as anything else, it is all in a lifetime. Why don\u27t you arrange to pass the autumn in the east? I will show you a country you...