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I I I I I I I I I I I I I I I I I I I - 119 - the centers of these crystals, but in some cases the crystals did not have a distinct embryonic center. Also, many of the star-like crystals and thick plates were asymmetrical in shape although they did not have a frozen droplet at their center. Furthermore, frozen drops were sometimes observed at the centers of crystals which showed no evidence of double growth. However, in some cases frozen drops were present at the centers or crystals which exhibited double growth. The fact that our observations do not confirm those of l-leickman et al., Auer and Veal, and Auer could be due to differences in the nature of the' clouds. The crystals observed by loleickmann et al ~ were ~own in a cloud chamber, and Auer and Veal's and Auer's observations were made in cap clouds. Our results, on the other hand, are based on crystals collected in the relatively deep cloud systems associated with Pacific Northwest storms. 4.2.18 Isolated Branches Branches may break away from star-like crystals at the points where the arms .taper to join the center of the crystal. It appears that when a branch " is fragmented from its parent star-like crystal, it is not well balanced. It may therefore undergo oscillations, rotations, and tumble as it falls through the air. As a consequence the branch often grows irregularly. A common characteristic of these isolated branches is their broad width. They often. have a much smaller length to width ratio than similar branches connected to star-like crystals. This may be due to the fact that when a branch is part o~ a star-like crystal, its close proximity to neighboring hranches results in preferential growth of the tip. . In addition, many of the isolated branches appeared much thicker than comparable branches attached to star-like crystals.