  There are 509 expanding neutral hydrogen shells catalogued in the Small
Magellanic Cloud (SMC), all apparently very young, with dynamical ages of a few
Myr. To examine their relationship with young stellar objects we
cross-correlated the shell catalogue with various catalogues of OB
associations, super giants, Cepheids, WR stars, supernova remnants, and star
clusters. The incidence of chance line-ups was estimated via Monte-Carlo
simulations, and found to be high. However, it is important that there are 1.5
times more shells that are {\em not} spatially correlated to an OB association,
than shells that are. Moreover, 59 of the 509 shells lie mainly in low stellar
density fields and have no young stellar objects associated with them, and
therefore no obvious energy source. It is shown that, on the whole, the
properties of these "empty" shells are very similar to the properties of the
rest of the shells, once selection biases are taken into account. Theoretical
implications of the results are discussed.
