THE ORIGIN OF THE EARTH. 



25 



entered the atmosphere in many, if not most, cases. This implies 

 that they are portions of larger bodies, and that they were not aggre- 

 gated, as such, in free space (Figs. 1, 2, 3, and 4). At least this appears 

 true in the case of most of the more massive meteorites that reach the 



Fig. 3. — A nickel-iron meteorite of irregular form, showing obviously that it is but 

 a fragment or remnant. The pits of the surface are due to the removal of the 

 less stable material, probably silicates or metallic compounds, by which the nickel- 

 iron was surrounded. Canyon Diablo meteorite, 265 lbs. Field Columbian 

 Museum. (Photo, by O. C. Farrington.) 



surface of the earth. This of itself does not exclude the view that 

 meteoroidal aggregation may take place in free space, and that the 

 aggregates may have entered into the make-up of the larger body from 

 which the meteorites were derived. It, however, bears on the ques- 

 tion whether meteorites, as a rule, were organized, as such, by the 



