| Brooke Bond | PG Tips tea cards offered in the interest of education | Small Wonders


	01 CACTUS Water conservation Cacti grow in dry places, including deserts, where rain is infrequent These plants are adapted for life in harsh climates by having thick fleshy stems covered With a waxy coating, which helps to retain the valuable water. The close-up photograph shows the long spines which protect the cactus from browsing animals and the lack of leaves means that no water is lost by evaporation.
	02 STINGING NETTLE Stinging mechanism All over the stern and leaves of a stinging nettle are sharp-pointed single celled stinging hairs. The base of each hair is thin walled and swollen with cell sap. If your skin brushes against a stinging nettle, it breaks off the glass-like tip on each hair, which can then pierce your skin. Wherever the sap which contains sodium formate, acetyl chorine and histamine enters your skin, it causes the unpleasant swelling as well as the stinging pain.
	03 SUNDEW Insect eating Plants which live in bogs where the soil is very poor, gain extra nutrients by trapping insects with their leaves. When an insect lands on a sundew, its legs and wings get caught on the sticky tipped tentacles like flies on fly paper. The attempts of the struggling insect to free itself make the tentacles bend over, forming a tight trap. The insect's body is then broken down by enzymes released by the tentacles, so that the nutrients inside it can be absorbed by the sundew.
	04 FERN FROND Spore formation Ferns reproduce by spores not by seeds. They develop inside sporangia which arise on the underside or the margins of the fern fronds. On this maidenhair fern, they develop along the margins of the mature fronds. In the close-up photograph six sporangia can be seen beneath a protective cover. When the spores are ripe, the cover dries and shrivels up and the sporangia burst open.
	05 MAGNOLIA LEAF Venation The blade of a leaf is strengthened by a network of veins, which may be parallel or may branch out from the central midrib. Each vein contains vascular bundles, which are a system of tubes for carrying water and food to the leaf cells. When a leaf falls from the tree the cells get broken down by insects feeding on them and by bacterial decay. The tougher veins persist as the leaf skeleton.
	06 FLOWER Stamens and Stigma he colourful outer parts of a tulip flower help both to protect the inside parts and to attract insect pollinators. The six pollen-bearing stamens surrounding the central style and stigma can be seen In the close-up photograph. The flower is pollinated when siting insects bring pollen to the Stigma from he stamens of another tulip flower. A pollen tube from each male pollen grain grows down side the style. When one reaches the female tube it is fertilized and can develop Into a seed.
	07 BEECH LEAF Leaf miner The larvae 01 some moths and flies live inside leaves between the upper and lower surfaces. Known as leaf miners, these larvae move through the leaf tissues, as they munch away on the middle layers. In the close-up photograph, the live larva can be seen inside the beech leaf feeding at the edge of the brown patch. As it eats away the cells containing green chlorophyll, the leaf turns brown. The mine starts off as a narrow track. widening as the larva grows.
	08 HORSE CHESTNUT leaf scar Beneath the bursting horse chestnut bud is the horseshoe-shaped leaf scar marking the place where a leaf was attached the previous summer. During the autumn, a layer of cork was laid down at the base of the leaf stalk. When the leaf fell off the twig, the sealed scar prevented moisture being lost from the tree. The dark spots on the scar, mark where the vascular bundles which carried the sap passed through from the twig into the leaf.
	09 FERN Fronds uncurling Ferns are green plants which do not flower. New leaves or fronds grow up from the underground rhizome. When the young fronds first appear they are quite tightly coiled. As the internal cells grow and enlarge, the fronds gradually unfurl and elongate. The close-up photograph shows the beautiful symmetry of an unfurling fern which is reddish at first, later turning to green.
	10 DANDELION SEEDS Dispersal Mechanism After flowering, a dandelion head develops brown hooked fruits, each with a stalked hairy mini-parachute. The number of puffs taken to blow away the parachutes making up the head of the clock' is supposed to tell the time of day. This old custom gives rise to names like clock flower' and what o'clock. Dandelion fruits are naturally dispersed by wind blowing the parachutes 4 metres or more above the ground and away from the parent plant.
	11 HONEYBEE Pollen baskets When a worker honeybee visits a flower, it collects both nectar and pollen. As the bee walks over a flat flower or enters a tubular one, it picks up the microscopic pollen grains on its body. These are cleaned off by a brush on each of the hind legs and tightly packed into the pollen basket. also on each hind leg. Both photographs show how the bee carries the pollen load back to the hive. Not all pollen is yellow, some flowers have green, or white or even black pollen.
	12 BUTTERFLY Proboscis The close-up photograph of the butterfly shows the partially extended proboscis. A butterfly feeds on liquid nectar by uncoiling the proboscis, which is kept extended by special muscles. Butterflies which feed on deep-throated flowers, such as honeysuckle, have an extra long proboscis for reaching the nectar food. The liquid nectar is sucked up through the hollow proboscis by a pumping action of the pharynx. When a butterfly stops feeding, it withdraws the proboscis and coils it up so tightly it is almost invisible.
	13 EARthWORM Bristles The earthworm body is divided into many segments; on each one there are four pairs of hooked bristles or chaetae. If the front end of a worm is touched by a bird, it stimulates the bristles to point towards the head. This gives the worm a better grip in its burrow and so makes it more difficult for it to be pulled out The bristles also help the earthworm to burrow, by anchoring part of the worm so the rest of the body can contract down.
	14 SPIDER Silk Production All spiders' webs are made of silk secreted by silk glands as a viscous liquid which hardens In air. A spider spins its web by pulling out silken threads from the six Spinnerets at the end of the abdomen Each gossamer thread is a mere 1/200 mm in diameter, and yet its elasticity and tensile strength far exceeds steel wire of a similar thickness. If a spider Spun a thread all the way round the world, it would use only 6 oz of silk
	15 MOth Antennae The mate emperor moth has elaborate feathery feelers or antennae. It uses these to find its mate. When she hatches out of her cocoon she produces a powerful scent which the male moth detects with his antennae. He flies towards the scent and mates with her. The scent of the female, is so strong that one moth placed in a meshed cage has attracted over twenty males to the outside.
	16 DADDY LONG LEGS Balancing organs like all true flies, daddy long-legs have just one pair of membranous wings for flight Only when the Insect is resting, can the tiny pair of club- shaped hind wings be seen These modified wings - known as halters give no lift or thrust to the flying insect, but are used for balance. They vibrate during flight at the same frequency as the wings, but out of phase With them. If the haltered are removed, the night becomes haphazard and . uncoordinated.
	17 HONEYCOMB Symmetry Honeycomb is made of wax secreted by worker bees from special wax glands. The hexagonal shape of each cell not only gives a beautiful symmetrical pattern, but it also gives the strongest construction with the minimum amount of building material and the maximum volume for storing honey and pollen. Note in the close-up photo, how the cells on the opposite side of the comb are completely offset, so giving greater rigidity. The cells are inclined at an angle so that the liquid honey will not run out before the cells are capped.
	18 trEE HOPPER Thorn mimic Tree hoppers are bugs which feed by sucking sap from plants. The thorax of this thorn bug projects forwards and upwards into a point which resembles a rose thorn. Notice how the bug comes to rest on a rose twig with its 'thorn' pointing in the same direction as the real thorns. The thorn bug is one of many Insects which mimic natural objects and help to deceive would-be predators.
	19 BUTTERFLY Wing Scales The patterns we see on butterfly and moth wings are made up of masses of dust-like scales. Both sides of the wings are covered with these microscopic scales which overlap each other like tiles on a root, as in the detailed photograph taken down a microscope. We recognise each kind of butterfly by the colour pattern of the scales. If the scales were to be rubbed off, the transparent wing, strengthened by veins, would be seen.
	20 THE CATERPILLAR False feet As as the three pairs of true legs at the front end of the body, caterpillars have up to five pairs of fleshy false feet or prolegs on segments 3-6 and 10 of the abdomen. The flat end of each proleg is armed with a semi circle of tiny hooks called crochets which grip so tightly to any branch that it is virtually impossible to pull off an unwilling caterpillar.
	21 CUCKOO SPIT Frog hopper In spring white froth or cuckoo spit is a fairly common sight on many plants. The spit is not made by cuckoos, but it appears about the time the cuckoos start calling. It is a tiny nymph of a frog hopper which makes the spittle by blowing air through a secretion from it's abdomen. The spit helps to protect the delicate hopper from drying out and from being seen by predators.
	22 HORSEFLY Compound Eye The most conspicuous part of a fly's head is the large pair of compound eyes. This horsefly has beautiful iridescent compound eyes. each one built up of some 4000 six sided cone shaped facets or ommatidia which interlock with one another like honeycomb cells. Each facet has its own tiny lens and forms a separate image. Together, the images produce a mosaic picture of the fly's field of vision.
	23 SILKWORM Cocoon The silk moth is a completely domesticated insect. The caterpillar, or silkworm, feeds on mulberry leaves and when fully grown it spins a silk cocoon around itself from a single filament of pale yellow silk about 300 metres long. The silk is secreted by silk glands as a fluid, later hardening into the tough fibre. The silken thread emerges from the spinneret at the front of the silkworm.
	24 WASP Hatching Wasps build their nest by scraping wood from fences and posts and chewing it into a paper pulp. Inside the nest, the queen wasp lays a single egg in each six sided cell. The grubs which hatch are fed on chewed up insect remains. When they are fully grown, the cells are capped and the wasp emerges head first by biting its way out through the cap.
	25 APHIDS Virgin Birth Aphids are well known garden pests which vary in colour. The reason they are such widespread and abundant insects is that a single female can produce up to 50 live young aphids, without finding a mate. After only 8-10 days the young are capable of reproducing themselves. When a female produces young from unfertilised eggs, it is known as virgin birth or parthenogenesis.
	26 STARFISH Tube Feet In grooves on the underside of the starfish are many suckered feet called podia. These tube feet are part of a system of water- filled canals. When more water is pushed into a suckered foot, it extends and when the water is withdrawn. the foot contracts. A starfish can move not only over flat rocks, but also up vertical ones by extending the tube feet on the leading arms and applying the suckers to the rock. As the attached feet are contracted, the body is pulled upwards.
	27 MUSSELS Siphons When exposed to the air, mussels close up their shells, only to open them again when covered by the incoming tide. The close-up photograph shows two mussels feeding underwater with a pair of siphons projecting between the open shells. Inside the mussel, microscopic hairs beat together, to draw sea water with plankton, in through the frilly siphon. The plankton is strained off by the gills as food, and the waste is ejected with sea water out through the plain siphon.
	28 FROG SPAWN Developing embryos Frog spawn is laid as a tight mass which first sinks. As the layer of jelly around each egg takes up water and swells, it floats to the surface. The jelly protects the developing embryos from being eaten by fish and ducks. At first, the egg can be seen as a tiny black sphere, but as the cells divide, it elongates. The beginnings of a head and a tall can be seen in the close-up photograph.
	29 WATER FLEA Movement Water fleas are freshwater crustaceans which breed rapidly when there is plenty of planktonic food available. In clear pond or canal water they can be seen as tiny yellowish or red specks moving jerkily through the water. They swim upwards by a vigourous downward movement of their long branched antennae against the water. Gradually they sink back to their original positions, only to repeat the performance.
	30 FISH SCalES Function The scaly coating on a fish's body gives it a protective, but flexible covering. Each scale is a bony plate which is formed and embedded in the skin. Together, they make a complete covering by overlapping each other like tiles on a roof. As scales continue growing each year, they give a permanent growth record rather like the growth rings of trees. If a fish biologist looks at a single fish scale under a microscope, he can identify the species and age it from the growth rings.
	31 FOX Fur A hairy coating is a feature common to all mammals. The red fox has reddish brown fur which, unlike the Arctic fox, does not turn white In winter. Pigment granules in the hairs give them their colour, so that when no pigment is produced, no colour is formed. The close-up photograph shows the long coarse guard hairs which overlie the soft dense woolly underfur. A fox loses its fur each year by molting from late spring through to autumn.
	32 HEDGEHOG Spines A hedgehog uses its spiny coating to help defend itself against predators. Only the back of the hedgehog is covered with spines, so that when alarmed, it rolls itself up Into a tight prickly ball. The soft unprotected belly is then tucked safely inside and the tough brown and yellow spines erected outside Newly born hedgehogs have soft spines, which take about three weeks to harden. They are more widely spaced than In the adult which has about 100 spines per square inch.
	33 CHAMELEON Colour Change Chameleons are predatory reptiles which are masters of disguise. They are able to change the colour of their skin so that It blends In with the surrounding leaves. Scattered all over the skin are branching pigment cells or chromatophores which are under nervous control. The chameleon skin darkens when the dark cells expand and the light cells contract; and lightens when the light cells expand and the dark cells contract.
	34 HUMAN SKIN Function The skin which covers our bodies has many functions. It protects the underlying tissues and contains numerous structures which are sensitive to temperature and touch Hairs emerge from all over the skin surface. The colour of the hair depends on the absence or presence of the pigment melanin, The shape of each hair is determined by its cross section. In straight hairs it is circular and In wavy hairs it is elliptical. .
	35 TOAD Skin Toads have a much drier and wartier skin than their close relatives the frogs. But like all amphibians, since toads do breathe partly I through their skin it must be kept fairly moist This is done by mucous secreted on to the skin. Toads also secrete a noxious substance which helps to deter predators from attacking them. The outer skin is shed several times each summer.
	36 SOAP BUBBLES Colour spectrum A soap solution has a low surface tension and so it easily forms thin films and bubbles Single bubbles are perfect spheres, but when massed together as a foam they are hexagonal. Light is reflected and refracted both outside. and inside the bubbles. This produces rainbow-like iridescent colours which vary as the thickness of the soap film changes. The flashlights used to photograph the soap bubbles highlight the intensity of the colour spectrum.
	37 SNOW FLAKE Crystal formation The snow flakes we see falling to the ground are made of many microscopic snow crystals. These crystals form in snow clouds when there is no wind and the temperature is near freezing. The breathtaking beauty of the symmetrical hexagonal (six-sided) crystals can be seen only by looking down a microscope. Since no two crystals are . identical, the shape of each one can tell scientists about the air currents and temperatures which it passed through on its journey to the ground.
	38 DOMESTIC SUGAR Crystal formation Raw sugar or sucrose is produced in large amounts by both sugar cane and sugar beet. The cane yields a syrup which evaporates to leave brown crystals. White sugar is then produced by purifying the brown sugar. Square sugar crystals form by their molecules building up into a regular and continuous three dimensional pattern. Their growth can be seen by dissolving sugar In a little water and leaving the solution to evaporate on a flat plate.
	39 MOULD Sporangia There are always microscopic spores of moulds present in the air, so that when food is left uncovered out of a refrigerator, moulds soon begin to grow. If you look closely with a hand lens at black pin moulds you will be able to see tiny black spheres attached to thin stalks. These contain millions of spores .which are released into the air when the spheres burst
	40 WHEAT Grains Wheat is one of several important grain crops grown by man. About three million acres of wheat are grown each year by British farmers. When the seed head has ripened, the corn is threshed to remove the protective outer sheaths, known as chaff, from the wheat grain. Each grain is a fruit rich in starch, as well as fats, proteins, minerals and vitamins. Wheat is chiefly used for flour and cereals.
	Photgraphed and described by Heather Angel

"A man that has 2 haircuts - both of them bad"
[http://Spaghoops.com/squelch/smallwonders.htm]