The truth about the stork

This was a one-off 'sex instruction' book for children. As far as I know Dr Griffith had never written anything for children before. It was illustrated by Hanna and Barbera (not sure of spelling here) and possibly before they became very famous themselves. Published by Gowers. I cannot remember that it went into more than one printing. I remember enjoying reading it but for some reason did not acquire a copy myself.