  We analyze canard explosions in delayed differential equations with a
one-dimensional slow manifold. This study is applied to explore the dynamics of
the van der Pol slow-fast system with delayed self-coupling. In the absence of
delays, this system provides a canonical example of a canard explosion. We show
that as the delay is increased a family of `classical' canard explosions ends
as a Bogdanov-Takens bifurcation occurs at the folds points of the S-shaped
critical manifold.
