  We argue that M2 brane is realized as a topological soliton on a coincident
pair of M5 and anti-M5 branes, as the two five-branes annihilate each other.
Topology and quantum numbers of this world-volume soliton are discussed in some
detail, and its formation is explained qualitatively. It follows from a
compactification that a D4-anti-D4 pair annihilate and produce type II
fundamental strings. The phenomenon is best described as the confinement of a
world-volume U(1) gauge field on D4-anti-D4, where the confined electric flux
string is identified as the fundamental string. This generalizes to other
D$p$-anti-D$p$ systems, and solves a puzzle recently pointed out by Witten.
