So you were astonished at Mrs. Gray’s audacity. Well, “toujours l’audace;” she is all the better for it. Some horseback work in getting to and into the Yosemite Valley was severe, but she bore it so well that I ventured, when we made our detour into the Colorado Rocky Mountains, to take her up to the summit of Gray’s Peak, 14,300 feet, or thereabouts, where she acquitted herself nobly. The day was perfect, the success complete, and the memory of it one of the most delightful of the many pleasant memories of the whole journey. Our great trip was the round from San Francisco to Mariposa Grove, Yosemite Valley, entering over Glacier Point, from which (tell your sons) is a new trail down the 4,000 feet into the valley; made excursions from the valley during several days, and returned by a long sweep through the little Tuolumne grove, round foothills to Murphy’s and the Calaveras Grove, and so back to San Francisco. Afterwards Mrs. Gray and I went to Santa Cruz and up the San Lorenzo Valley among noble redwoods, rivaling the Sequoia gigantea. On return we made one stretch to the east base of the Rocky Mountains, then down to Denver, and up into the mountains, to 8,400 feet, where we had a pleasant week or more (just the climate to give strength to an invalid), whence I climbed a high mountain or two, among them Gray’s Peak, the highest, as already mentioned. Thence we came down to Dubuque and hot weather, on the Mississippi to St. Paul and St. Anthony, etc., and then home by rail, having been twelve busy weeks away. Well, we are longing to do it again, and more! But I am settling down to my work as well as I may, well content with the summer’s holiday. December 2, 1872. Well, it is wonderful, your finding the nervous system of Dionæa!!! Pray take your time next spring, and do up both Drosera and Dionæa. I will endeavor next spring to get hold of Drosera filiformis and make the observations. I will also do better, by sending your note on to Mr. Canby, who lives near its habitat, and has done something already in such observations. As to coiling of tendril. I think your idea is that in the coiling of a fixed tendril, one coil has its concave side the opposite of the part that has coiled the other way. Now take a piece of tape say a span long; black one side, let some one hold the two ends while you twist in the middle. The two halves are coiled in opposite directions, just as a tendril which has caught does. The same color will be on the outside of the coil all the length. Blacken with a stroke of paint a line along the whole length of a caught tendril. On straightening it out the black will be all on one side. I have not had time to follow it up, and need not, since you are sure to do it. But I think it clear that one and the same side is concave, that is, the relatively shortened side, the whole length of the caught tendril. Do not you?