Later he obtained an Engineering degree at Peterhouse, Cambridge, and in 1924 joined the RAF. After a routine peacetime career his critical appointment came in 1937.
When Sir Henry Tizard and his colleagues first demonstrated the potentialities of radar (or Radio Direction Finding as it was then called), there were many who remained to be convinced of its practical application to air defence – and indeed of the real validity of any air defence (“The bomber will always get through,” Stanley Baldwin, among others, was quoted as saying). Among those who maintained faith in its practicality was Lord Swinton, the far-seeing Air Minister.On the airfield at Biggin Hill there was established an experimental flight of fighters designed to assess the merits, not only of radar, but of the whole concept of ground command and control, of which Air Chief Marshal Hugh Dowding, the recently appointed Commander-in-Chief of Fighter Command, was such a fervent advocate. Swinton told McDonald at the time of the experiments: “I hope you realise that the whole future of this country depends on the results which you obtain at Biggin Hill.”The results produced convinced even the most sceptical of observers. This amazing creature has no fewer than 16 pigments, six of them in the ultraviolet spectrum.

As yet, we have little idea of how this incredible array is integrated or how it is used. A major problem for researchers is that, after one meal, mantis shrimps are often inactive for days.Quite a number of aquatic animals have UV vision which they use for hunting and to avoid being eaten themselves. The “nightclub” effect of ultraviolet – putting objects into sharp contrast – is very useful because, without it, the silvery bodies of fish become almost invisible in the sea Among salmon, only the juveniles can see UV. This is because they stay near the surface and feed on plankton, which reflects those wavelengths. But we can only contemplate in awe the capabilities of the mantis shrimp, the colour vision champion of the animal world.

Seeing UV probably involves the same brilliant contrasts that we experience under long-wave ultraviolet light in a nightclub, where every speck of dandruff shows up on the shoulders of a dark suit – but with the benefit of full colour as well.Human colour vision is composed from three pigments, and we can just about take a stab at imagining what it must be like to be a bird with four, or even five, pigments – a range which makes our much-vaunted 16 million colours on a TV monitor look pretty lame. Animals with UV capability have a similar range available to them between blue and ultraviolet that we lack completely. “Many behaviour studies, especially on birds, will have to be junked.”
Not just birds: a recent report in “Trends in Ecology and Evolution” pointed out that spiders’ webs, far from being passive devices that insects fly into, actually lure them in by reflecting UV. In fact, some spiders whose silk is not UV-reflective put UV reflecting strips on their webs, and increase their capture rate as a result.

The UV factor is only just beginning to be taken into account.To get an idea of how much humans are missing by not being able to see in the UV range, just visualise the rich gradation of colours we can see between red and green. Humans can’t see the short- wave ultraviolet (UV) end of the spectrum, but most birds and insects and some reptiles can. “Without an adequate understanding of the perceptual cues to which an animal is responding it is impossible even to start to explain its behaviour,” says Dr Martin Tovee of Newcastle University. Imagine being able to see the world in black and white only.

The attraction of sunsets, flower gardens, coral reefs and most painting would be lost on you. Then imagine that for some reason people couldn’t explain about colour to you, but you had to find theories to explain why they spent so much time daubing at canvas or snorkelling Most of your explanations would probably be pretty daft

This is not an idle exercise. It pretty well describes the problems that arose in study- ing animal behaviour until very recently. Past experience with B thuringiensis also suggests that mosquito-killing bacteria with similar toxins can be deployed safely.Yet key concerns remain. Will toxin genes transfer to other species? If so, with what consequences? And will the genes be inactivated anyway, after the toxins have done their work, since they will be of no lasting value to the microbes carrying them? Only when such questions have been answered satisfactorily can this potentially highly beneficient technology be applied with confidence.. Moreover, toxin genes from bacillus can be inserted into caulobacters’ DNA.Experiments conducted thus far suggest that the engineered microbes produce only small quantities of the toxins, although this needs to be offset against their much greater persistence at the water surface.With more than 400 million people living in highly malarious areas of the world, and existing methods of controlling the disease faltering seriously, the need for a new approach is obvious. Another, perhaps in combination, is to engineer a toxin-carrying microbe that does not sink to the bottom when sprayed on water.While investigators have made some progress by moving genes between different species of bacillus, the most promising avenue may be to place the toxin- producing genes into unrelated bacteria that have other desirable characteristics.