Equally so as it ha been in his own, over the estuous rivers of Lapland, or its frozen and cacuminous mountains;

The human species was lucky, because the only time in the development of bacterial populations when diversity is sacrificed for reproductive expediency is during the exponential burst of growth that follows their discovery of an unprotected ecosystem. The two notable instances in which bacteria find these Shangri Las are in test tubes filled with fresh media and in naive animals that have not seen these particular bacteria in recent immunological memory.

As towns continue to grow, replanting vegetation has become a form of urban utopia and green roofs are spreading fast. Last year 1m square metres of plant-covered roofing was built in France, as much as in the US, and 10 times more than in Germany, the pioneer in this field. In Paris 22 hectares of roof have been planted, out of a potential total of 80 hectares.

The row started over who will run for parliament in a wealthy rightwing constituency on the left bank in Paris, a safe seat for Sarkozy's ruling UMP.