ALLEGAN METEORITE AND MART IRON 43 



but that the broad side (lower surface in the figure) was first to 

 strike the Efround. These conclusions are based on the facts 

 that the crust at the top A, where friction would have been 

 greatest if this side had been foremost, is scarcely more than a 

 millimeter in thickness, and, as shown by the microscope, is 

 almost wholly glassy, enclosing only residual portions of un- 

 fused silicates ; while on the other side it is from 2 to 3 mm. in 

 thickness, blebby, and, as seen under the microscope, vesicular, 

 and often crowded with minute silicate crystallites imperfectly 

 secreted from the glassy base ^ (PL III, fig. 2). Further, the 

 furrows on the outer surface of the crust, due to atmospheric 

 friction, radiate in all directions from this uppermost point A. 

 These furrows show somewhat indistinctly near B in fig. i. 

 That the stone struck broad side down is shown by the grass 

 stems and earth still adhering to this surface. 



A point of no inconsiderable interest in this connection lies in 

 the fact that these grass leaves, which were wielded to the surface 

 of the stone through impact, or were even driven into the frac- 

 tures caused by the same, are not charred in the least, nor is 

 there other evidence of heat than that furnished by the black 

 crust already referred to. The grass leaves and earthy matter 

 adhering to the surface of the stone are shown somewhat in- 

 distinctly at C in PI. I, fig. I. 



To the unaided eye this stone shows on the broken surface a 

 quite even granular structure of gray color and, on closer in- 

 spection, abundant, beautifully spherulitic chondrules, averag- 

 ing not more than one or two millimeters in diameter (PI. II). 

 In two cases chondrules nearly 5 mm. in diameter w^ere ob- 

 served. These are sometimes beautifully spherulitic, or again 

 elongated and irregular in outline, and sometimes have pitted 

 surfaces, such as are seen in compressed pebbles in conglomer- 

 ates (see PI. IV, figs. 1-7). The majority of them are dark 

 gray in color, but some are greenish white. They are com- 

 posed of both olivine and enstatite, as will be noted later. Nu- 

 merous brilliant metallic points of a silver-white color indicate 

 the presence of disseminated iron. Viewed more closely the 



lA similar thickening of the crust at the rear (riickseite) was noted by 

 Tschermak on the Gopalpur meteorite (Min. Mittheil., 1872, p. 96). 



