Human Embryology, 3rd Edition, On the Beginning of Life

Human Embryology, 3rd ed. Bradley M. Patten, (New York: McGraw Hill, 1968), 43.

“It is the penetration of the ovum by a spermatozoan and resultant mingling of the nuclear material each brings to the union that constitutes the culmination of the process of fertilization and marks the initiation of the life of a new individual.”