THE STRUCTURE OF METEORITES 



175 



they may differ little in color from it. On this account and on 

 account of an ill-defined contour they may be overlooked and a 

 crystal may be considered porphyritic, which is really part of 

 a chondrus. Usually, however, the chondri are plainly marked 



Fig. 7. — Section of the Homestead meteorite, showing a typical eccentrically- 

 radiating bronzite chondrus (above) and a porphyritic chrysolite chondrus (below). 

 A granular chrysolite chondrus also appears at the left. X 65. After Tschermak. 1 



on a polished section by differences in color and contour. In 



structure chondri may themselves be granular, porphyritic, 



coarsely or finely fibrous. They may consist of a single crystal 



individual, in which case they are said to be monosomatic, or of 



several individuals, when they are said to be polysomatic. 



'Die mikroskopische Beschaffenheit der Meteoriten. Tafel VII, Fig. 4. Figs. 2, 

 3, 4 and 5 of Article I should also be credited to Tschermak, Lehrbuch der Miner- 

 alogie, 4th edition, p. 5V5. 



