The first flowers opened on August 3, and they have continued to open in succession, a belt about 3 in. wide opening each day. They remain in good condition for two days; on the third day the stamens wilt and drop down, but the pistil remains erect till the fourth day. On the first day of opening the pistil is not so long as the stamens by ¾ in.; on the second it has grown to be as long as the stamens, but it is not in condition to receive the pollen till after noon of the second day. Although the flowers on some eighteen inches of the spike have already blossomed, none of the ovaries have been fertilized; they are dropping off, but I am rather sanguine regarding those about the middle of the spike. So great is the superfluity of nectar contained in the flowers, that on the afternoon of the second day it often drops from the cups, and the least shake to the scape brings it down in a shower. The main beauty of the inflorescence consists in the dense bottle-brush-like mass of bright yellow anthers. This plant, together with several smaller ones, was contributed to this garden by Dr. Edward Palmer, who collected them in their native wilds--the mountains of Northern Mexico--some three years ago. He found them growing in a limited and rather inaccessible locality in gravelly and rocky soil some miles from Monterey. In addition to those he sent here he also sent a quantity to the garden of the Agricultural Department at Washington, and some to Dr. Engelmann, the eminent botanist at St. Louis. To Dr. Engelmann he also sent a piece of an old flower stem and some dried capsules which he found upon an old plant, and it was from these specimens in 1880 that the doctor was enabled to describe for the first time the inflorescence of this Agave.--_The Garden_. * * * * * ON THE CONSTITUTION OF THE NATURAL FATS. By J. ALFRED WANKLYN and WILLIAM FOX. In the course of an investigation in which we are at present engaged we have arrived at some results which appear to us to be very interesting. We find that the generally received view that the fats are ethers of glycerin is partially correct, and that instances of a different kind of structure occur among the natural oils and fats. Ethers of iso-glycerin, or of homologues of iso-glycerin, appear to occur. Iso-glycerin has this structure: C(OH)_{2} CH CH_{3} It exists in its ethers, but cannot be isolated, and should be resolved into: COOH + H_{2}O CH_{2} CH_{3} Ethers of iso-glycerin, or ethers of homologues of iso-glycerin, yield no glycerin when saponified.--_Chemical News_. * * * * * A catalogue, containing brief notices of many important scientific papers heretofore published in the SUPPLEMENT, may be had gratis at this office. * * * * * THE SCIENTIFIC AMERICAN SUPPLEMENT. PUBLISHED WEEKLY. TERMS OF SUBSCRIPTION, $5 A YEAR.