In biology conception is the coalescence of the male and female generative elements, producing pregnancy.
Have become obliterated by coalescence of their walls, so that the entire endoderm of the umbrella is in the condition of the endodermlamella.
In some hydroids the founder-polyp, developed from a planula after fixation, throws out numerous outgrowths from the base to form the hydrorhiza; these outgrowths may be radially arranged so as to form by contact or coalescence a flat plate.
By coalescence of the endoderm-layers, the coelenteron may be reduced to vessels, usually eight in number, opening into a ring-sinus surrounding the pore.
Laticiferous vessels arise by the coalescence of originally distinct cells.