THE STRUCTURE OF METEORITES 



179 



troilite. A gathering of grains at the center distinguishes these 

 chondri from those previously described in which the rim was 

 black. Besides complete chondri, fragments representing vari- 

 ous proportions of a complete chondrus occur. These may, on 



Fig. 9. — Section of the Mezo-Madaras meteorite, showing a meteoritic tuff made 

 up of fragments of chondri. Portions of bronzite, chrysolite and nickel-iron chondri 

 can be recognized. After Tschermak. 1 



account of their shape, be very misleading, as they may be taken 

 for porphyritic individuals or for portions of a foreign stone if their 

 previous chondritic origin is not recognized. Tschermak states 

 that fragments of chondri are most numerous in the stones whose 

 chondri have well-marked contours. So far as the association 

 of chondri is concerned it is to be noted that chondri of more 

 ^p. cit. Tafel XIX, Fig. 4. 



