There is tragic evidence to show that the paintings at the French prehistoric art sites are deteriorating.
South Africa had a long record of studies in prehistory, going back to the end of the last century.
The Foxhall jaw has now been missing for many years.
Although we followed that hyena for the best part of half an hour, we never caught up with it.
I kept an open mind on the question of whether a hominid had been present in Europe in the early Pleistocene.
At Olduvai, for 20 years, Mary and I had investigated and made a general survey of the overall geology.