Sponge Develoment Small 314×320 Medium 629×640 Large 1006×1024 Download Tiff Original 2400×2443 | (323.9 KB) Description The sponge, a many celled animal, begins its life as a single-cell, the egg. Second division into the four cell stage. Keywords sponge, sponge stages Galleries Sponges Source: Winchell, Alexander Sketches of Creation (New York, NY: Harper & Brothers, 1870)
