The scope of this undertaking exceeds the mere giving of advice to a parent concerning the vicissitudes of a particular developmental period, though it is much more restricted than the analytic treatment of either mother or child. The author illustrates the range of problems to be dealt with by this technique from case studies undertaken at University College Nursery School (Cleveland) which admits children already manifesting developmental disturbance. The criterion for treating the child through the parent is that the problem shall as yet not be completely internalized. Criteria for maternal suitability to undertake this work are difficult to ascertain or to apply in early psychiatric interviews. Amongst the less easy to ascertain in initial interview are those mothers who, while appearing insightful and generally balanced, have problems in areas which overlap those of the child's, or who share the child's defence mechanisms, precluding them from successfully sharing in the work. Where the mother also suffered in childhood from an identical symptom or where the child himself