  We address the formation and propagation of multi-spot soliton packets in
saturable Kerr nonlinear media with an imprinted harmonic transverse modulation
of the refractive index. We show that, in sharp contrast to homogeneous media
where stable multi-peaked solitons do not exist, the photonic lattices support
stable higher-order structures in the form of soliton packets, or soliton
trains. Intuitively, such trains can be viewed as made of several lowest order
solitons bound together with appropriate relative phases and their existence as
stable objects puts forward the concept of compact manipulation of several
solitons as a single entity.
