Excerpt from Journal of Morphology, Vol. 31: June, September, December, 1918 One can say positively, that the same small egg cells] are visibly distinguishable in no way from other young ectoderm cells, for one can always recognize the place at which later a germ zone will form and can demonstrate that in that place are no cells which could be SO designated [as germ cells]. The germ cells are therefore not in this case definitely contained in the colony from the beginning and dif ferentiated only at the time Of sexual maturity, but they arise only at this time out of a growing mass of young cells. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.