SEED-BEARING PLANTS 
425 
FIG. 315. The organization of shallow water accumulations in a lake 
of the present geological epoch, showing remains of roots, leaves, etc. 
Near the center of the figure may be seen a cross-section of the triangular 
needle of a white pine. (Cf. Figs. 316 and 317.) (After E. C. Jeffrey.) 
FIG. 316. Fine muck from the bottom of a pond, as seen under the 
compound microscope, showing the presence of pollen grains of pine, 
spruce, and fir. (Cf. Figs. 315 and 317.) (After E. C. Jeffrey.) 
