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- 118 - l- I- l- I- 1- l l- I- l- I- l- I I I I I l I. l they were distorted, but they often had cracks. The frozen drops were sometimes rimed and on occasions had collected other ice particles. The drops in anyone storm were fairly uniform in size. Frozen drops were observed as large as about 1000 ~m in diameter, However, most of them were between 250 to 500 ~m in diameter on the ground and 50 to !.l00 ~m in the air, In regions where there was an increase in air turbulence, there was also an increase in the concentration of frozen drops, 4,2,17 Frozen Droplets at the Centers of Crystals The occurrence of a frozen drop at the center ofacrystal may provide information 'on the mode of nucleation (Weickman, et al., 1970; Auer and Veal, 1970; Auer, 1971). Also, a frozen drop at the center of a crystal implies that the atmosphere was initially supersaturated with respect to water. Very few crystals out of the many tens of thousands which we have examined had frozen drops at their centers. A rough estimate would indicate that of the crystals collected in the air less than one crystal in a thousand had a frozen drop at its center. The same extreme scarcity of crystals with frozen drops at their centers was also noted on the ground. Weickman, et al., Auer and Veal, and Auer have suggested that asymmetrical plates are more corm;'::'ti with a frozen drop at their center and that a frozen drop is generally associated with double growth about the center of the crystal. Our observations to date do not lead to any such general conclusions. For example, double growth was often observed on both thick plates and isolated brcmches and yet no frozen droplet was observed at the centers of these crystals. Als.), frozen droplets were rarely found at the centers of star-like crystals. Irregular blocks of ice, hexagonal plates and solid columns were sometimes at