. Carnegie Institution of Washington publication. GENUS HTMENOCALLIS. 649 Chart No. 219. GV S T CI CA PA FC PS 01 PA CA The lamellas are not always demonstrable, especially near the hilum, but are distinct in a greater number of grains than in H. undulata. When observed near the hilum they are in the form of circular or oval rings, but most of the lamellae follow closely the outline of the grain. One quite refractive lamella is often seen at varj'ing distances from the hilum, and sometimes there is a band of very fine, indistinct lamellae at the margin of the grain. On the large grains frequen
. Carnegie Institution of Washington publication. GENUS HTMENOCALLIS. 649 Chart No. 219. GV S T CI CA PA FC PS 01 PA CA The lamellas are not always demonstrable, especially near the hilum, but are distinct in a greater number of grains than in H. undulata. When observed near the hilum they are in the form of circular or oval rings, but most of the lamellae follow closely the outline of the grain. One quite refractive lamella is often seen at varj'ing distances from the hilum, and sometimes there is a band of very fine, indistinct lamellae at the margin of the grain. On the large grains frequently 16, rarely 20 to 22, lamellae can be counted. The lamellae are more distinct, but of the same general character as in H. undulala. The grains vary in size; the smaller are 4 by S/z; the larger, elongated ones are 36 by 38/*, and the broadened forms are 36 by 44;u in length and breadth. The common size is about 24 by 22/i in length and breadth. Polariscopic Properties.—The figure is centric, eccentric, or of the bean type; more often centric or nearly centric than in H. undulata; and while the lines are of similar character and arrangement with those of that species they are more often straight. The degree of -polarization is high, rather higher than in H. undulata. The same variation is found among the different grains, but the proportion in which the polariza- " tion is very high is greater than in H. undidata. There is less variation in the same aspect of a given grain than in H. undulata. With selenite the quadrants are well defined, and many are regular in shape and equal in size. The number of grains in which they are regular is greater than in H. undulata. The colors are generally pure, but sometimes have a greenish tinge, or the margin of the yellow quad- rant may be orange in tint. The colors are more often pure than in H. undulata. Iodine Reactions.—With per cent Lugol's solu- tion the grains color a rather deep blue-violet, which deepens rapidly, the
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