primordium

noun

1. An aggregation of cells that is the first stage in the development of an organ.

   “In tomato, for example, the first sepal primordium is formed as an outgrowth at the periphery of the apex and the subsequent sepal primordia are initiated in a helical fashion at an angle of approximately 137° from the previous one.”

2. A primordial, original condition or event.

   “It is thus vain to hope that the history of the primordia can be reduced to the progress of archeological investigation.”

   “Attempts have been made by historians of religion to distinguish between mythic orientations in time concerned with the repetition of a primordium and those concerned with the anticipation of an eschaton.”

   “[Joseph Smith] did not think of himself as going back to a primordium of true Christianity, as the Puritans did. In his view, there never was a golden age when religion flourished to perfection.”