EXPLANATION OF PLATES. 
Plate 7 .—Sections of spherulites. 
Figure 1.—Colorless microscopic spherulite, showing irregular dark cross 
between crossed nicols, enlarged 153 diameters. 
Figure 2.—Simple form of granophyre group of quartz and feldspar 
between crossed nicols, enlarged 235 diameters. 
Figure 3.—Microscopic spherulite with projecting rays of orthoclase, 
enlarged 120 diameters. 
Figure 4.—Like figure 3, with crescent-shaped area of pure feldspar 
substance, enlarged 130 diameters. 
Figure 5—The same as figure 3, enlarged 120 diameters. 
Figure 6.—Portion of large spherulite, showing different forms of feld¬ 
spar needles. 
Figure 7.—Branching group of orthoclase needles occurring in the outer 
portion of the spherulite of figure 6. 
Plate 8. —Branching crystals of orthoclase. 
Mannebach twins, enlarged 43 diameters. 
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