THE BEGINNING OF LIFE ON THE EARTH. 31 



Fig. 17. — Magnified group of canals in supplemental skeleton of Eozoon. 

 Taken from the specimen in which they were first recognised {Life's Dawn on Earth). 



Fig. 18. — Portion of Eozoon magnified loo diameters, showing the original cell-wall with 

 tabulation, and the supplemental skeleton with canals. — After Carpenter. 



a. Original tubulated wall or"Nummuline layer." More magnified in Fig. A. b, c. 



Intermediate skeleton, with canals. 



