(Full details on BBC1 at 4.0 pm)

Royal Institution Lectures by Professor Eric Laithwaite
2: Tweedledum and Tweedledee
Lewis Carroll 's twins are symbolic of our concept of left and right. Objects which from certain viewpoints have no left and right introduce the subject of symmetry: wheels, cylinders, and to a limited extent bricks and cubes, have a symmetry that the optical mirror fails to detect-until they move: when a wheel spins the mirror appears only to reverse time!
Presented for TV by BRIAN JOHNSON

returns to the air and, as from this evening, is presented by Michael Charlton
Every weekday evening an interview with a man or woman behind the headlines follows the News Summary and Weather report
Associate producer JOHN SHEARER Producer CHRISTOPHER CAPRON

Public School for Dogs
Pen Andrews grew up In the Yorkshire village of Royston. His neighbours had two things in common - mining and whippet-racing. At 18 he bought his first greyhound, but it was another 30 years before he plucked up the courage to turn professional trainer. Now in his 60s, Pen is headmaster of the Yorkshire Public School for Dogs. Locally, he is counted a great success, but Pen wants to extend his personal empire a little further.
Executive producer JENNIFER JEREMY
Director DESMOND LAPSLEY (Birmingham)

Starring Ben Murphy as Jones and Roger Davis as Smith
with guest stars Buddy Ebsen, Rod Cameron, Marie Windsor

Rancher Phil Archer hires Smith and Jones to trap wild animals-but Archer plans to trap the boys themselves...

A duel of words and wit between Frank Muir
The Marchioness of Tavlstock Edward Fox and Patrick CampKll
Pauline Collins , Antony Hopkins Referee Robert Robinson
Devised by MARK GOODSON , BILL TODMAN Director MICHAEL GOODWIN Producer JOHNNY DOWNES

The Lysenko Affair by JOHN WILES
In 1948 a sentence of death was passed on a whole branch of Russian science. Laboratories studying genetics were closed, text books destroyed, and scientists were imprisoned.
One man, TROFIM LYSENKO. an agriculturist with no formal scientific training, had so exploited the political situation of the time that a whole body of knowledge was replaced by his own ill-formed theories. It was a tragedy from which even today Russian agriculture has not recovered.
How he achieved this throws light on the vulnerability of science that no society can afford to ignore.
Students.HESSEL SAKS, DEREK WEST Narrator FRANK GILLARD
Producer PETER JONES Editor PETER GOODCHILD

Initiation by PETER KING
A bullying foreman, a new girl who has seen it all ... The new boy at the printing works goes through more than one initiation.
Script editor ALAN SEYMOUR
Designer GEOFFREY PATTERSON Producer ANNE HEAD
Director BRIAN PARKER

Presented by Peter Dorling Weather

by Satellite
The Third Test
Australia v England from Melbourne, New South Wales
RICHIE BENAUD introduces highlights of the fourth day's play.

Gabriel Woolf reads "Thrushes" by Ted Hughes