fission (fish on)

[L. fi io (n-), a cleaving, The human body is itself compounded of innumerable microscopic organisms, which multiply, as the infusorial monads do, by spontaneous fi ion . H. Spencer , Social Statics, p. 490. Multiplication is effected through fi ion: that is to say, each globule or filament, after elongating, divides into two segments, each of which increases in its turn, to again divide into parts, and so on. Quoted in Sci . Amer . Supp ., p. 446.