THE STRUCTURE OF METEORITES 



I8 5 



across that of the vein, and these may pass into empty clefts. 

 In many portions of the stone of Chantonnay narrow, irregular, 

 open fissures occur. Some of these have begun to be filled by 

 matter that has flowed in from the surface, but it has penetrated 

 only to a depth of a few millimeters. The vein substance 



Fig. 11. — Cross section of a vein of one of the Mocs meteorites. The vein mass 

 appears as a broad black band through the center. It is in part intermixed with the 

 adjoining groundmass and in part has well defined walls. The gray spots are 

 spheres and lumps of nickel-iron illuminated by reflected light. The branching of 

 some of these into clefts, one of which is still open, is of interest. X 20. After 

 Tschermak. 1 



usually has fairly well-defined walls, but on the other hand may 

 gradually pass into the body of the meteorite. In the stone of 

 Goalpara, which is coarsely porous, a black, vein-like substance 

 forms the walls of the pores, makes up the groundmass, and 

 'Op. cit. Tafel XXII, Fig. 2. 



