asked the Secretary of State for the Home Department how effective detention centres have been so far in checking criminal tendencies in young men under 21 years of age.

Reconviction figures for detention centres are given on page 52 of the Statistical Tables to the Prison Commissioners' Annual Report for 1962; I consider them encouraging, but evaluation of the effects of penal treatment is a complicated matter on which research is continuing. I refer the hon. Member to Part VI of the recent handbook The Sentence of the Court.

Have not detention centres now passed beyond the bounds of an experiment and become a stable part of the penal system, and is it not a fact that there are too few of them and there are difficulties in recruiting staff? What is the Home Office doing about it?

I think that we all agree with the hon. Gentleman that these centres are proving very valuable. At present, with the opening of an additional centre at Usk in Monmouthshire last month, there are now 15 centres in operation. Further measures are in hand.