 At this point, Attenborough realised that he had spent 20 years unconsciously assembling a collection of programmes on all the major groups of terrestrial animals and plants – only reptiles and amphibians were missing.When "Life in Cold Blood" was broadcast in 2008, he had the satisfaction of completing the set, brought together in a DVD encyclopaedia called "Life on Land".In an interview that year, Attenborough was asked to sum up his achievement, and responded