Most men and women like warm weather, but it is the so-called cold-blooded animals, and especially the insects, which are most affected by it. Thirty years ago the speed-up of insect life in London by hot weather always brought on an outbreak of summer diarrhoea which killed a number of babies. This was due to infection of their food by bacteria carried by flies. Plants also grow quicker in hot countries, provided they can get water. Probably this is why most human migrations have been towards warmer lands. In Europe the human stream has on the whole flowed westwards and southwards. In consequence the Scandinavian countries are the only ones which have never been conquered by foreigners, though they have sometimes conquered one another. One reason why the British officials in the Near East were mostly so hostile to Israel was of course that Labour was highly organized in Palestine and collective farms were proving successful.