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between the senses. But in time, and of necessity, an infant learns to sort and tame sensory impressions. The sense of smell supplies us unobtrusively, very strongly in the subconscious, with a constant stream of information about our surroundings, homely and unhomely, about family, siblings, mothers. Smell tells us much more about the people around us than we generally appreciate; it is designed to tell us about our kin, our genetic relation to others for the avoidance of inbreeding, which is linked with the quality of our immune systems. Grown women can recognise their offspring by smell, and pre-adolescent children can recognise full siblings but not half- or step-siblings. We are social beings and our sense of smell informs us continuously with useful social as well as environmental information. Among carnivores it is as important to be aware of each other as of prey. There is a smell clinic in Dresden where Dr Thomas Hummel’s researches show that women are typically better at discerning and then recognising olfactory signals. Hummel’s conclusion is that women continue to be more aware of smells as social signals because they tend to be more socially aware, and he observes that women come to his clinic for help because they are upset by the social effects of losing their sense of smell, and men come because they are missing the hedonic effects. Plants and insects The great evolutionary scheme of things seems to have created invertebrates as the servants of plant propagation. They developed to do the bidding of plants. Evolutionarily plants are clever, and imitative. Wind-pollinated plants came first and have little colour, little scent and huge amounts of pollen – think grasses. Plants pollinated by insects are entomophilous; they produce less pollen, but it is sticky and protein laden and such plants must expend energy on nectar production and must also communicate with their pollinators somehow; they must advertise through colour, pattern and smell. The real relationship between plants and insects began with beetle-pollinated plants in the early Cretaceous, around 120 million years ago, when a new pollination strategy developed, and flowering plants first appeared. It seems likely that beetles led the way in insect pollination, followed by flies. Beetle-pollinated plants tend to be dull in colour, rich, foxy, fruity, even stale in scent, and have prominent anthers heavy with pollen like Magnolia grandiflora. Fly-pollinated plants have little or no colour and little or no scent, although carrion-fly-pollinated plants come in flesh colours and have strong rotting-meat smells, like eucomis does. Bee-pollinated plants tend to have yellow and blue flowers and a fresh mild smell. In wasp-pollinated plants, colour is not important and usually dark, the scent is sickly sweet like that of Angelica gigas. Butterflypollinated plants must have a landing pad – this is more important than the colour – and the smell is generally fresh, sweet and light such as that of buddleia. Mothpollinated plants have light-coloured flowers which are more visible in the dark, and a strong sweet smell – perhaps the best of smells – for example, nicotiana.

Pollution is a huge factor in inhibiting pollination. A study done by the University of Virginia concludes that air pollution is definitely destroying plant fragrance and thereby inhibiting insect pollination. The difference in distance that scent molecules can travel in unpolluted air is between a thousand and two thousand metres as compared with less than a couple of hundred metres in modern major cities. This is because the volatiles emitted by plants in their daily converse


Oxeye daisies everywhere

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