But what was all this ignorance, compared with our utter helplessness in the presence of such a phenomenon as memory, or of that other more prolonged and astounding memory which we called the inheritance of acquired characteristics? Out of the question to get even a glimpse of any mechanical possibility of explication of such performances on the part of the cell-substance. The spermatozoon that conveyed to the egg countless complicated individual and racial characteristics of the father was visible only through a microscope; even the most powerful magnification was not enough to show it as other than a homogeneous body, or to determine its origin; it looked the same in one animal as in another. These factors forced one to the assumption that the cell was in the same case as with the higher form it went to build up: that it too was already a higher form, composed in its turn by the division of living bodies, individual living units. Thus one passed from the supposed smallest unit to a still smaller one; one was driven to separate the elementary into its elements.