THE ORIGIN AND DEVELOPMENT OF THE EARTH 115 
FIGURE 4. 
The great nebula in Orion, and the Fish-Mouth Nebula. There are 
several great nebulae of this type known, but these are the most notable 
They seem to have been co-partners in a mutual collision 
examples. 
Photographed at the 
at rates of many thousands of miles per second. 
Yerkes Observatory. From Chamberlin, University of Chicago Press. 
