Various species of the fruit-fly, Drosophila, have been used to prove numerous phases of MendeRs Law. Excellent results in accordance with the Mendelian Ratio were obtained in several experiments with Drosophila ampelophila. Drosophila was used because of the comparatively short time in which several successive generations can be procured. The average time for the development of the adult from the egg is ten to fourteen days, depending upon the temperature. On account of this fact two

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... s can be obtained in less than a month. Drosophila ampelophila Ferno Iff with Vestigia I Winds' Two varieties of Drosophila ampelophila were used: a wild variety having long wings with all the characteristics of the Diptera and a second variety having short vestigial wings but in other details like the first type. (See Drawings.) The object of the experiment was to ascertain how closely the ratio between longwinged and vestigial-winged descendants accorded with the Mendelian ratio for a single pair of contrasting characters in the parents. Mendel, after studying the phenomena of hybridization in the garden pea, deduced the ratio to be 3 :1 and explained and proved this ratio both in theory and experiment. Small six ounce quinine bottles were used as containers for the flies, the bottom of each bottle being covered with sour banana mash to a depth of half an inch or more. Several pieces