Images Dated 10th October 2000

Hazel pollen grains

Hazel pollen grains. Coloured scanning electron micrograph (SEM) of pollen grains from the Hazel tree, Corylus avellana. These microspores are shed from male catkins (hanging pollen-bearing structures) on the Hazel tree, released into the air and carried by wind to pollinate the female flowers. Pollen grain shape, size and surface sculpturing varies greatly between species, and may be used by botanists to identify plants from pollen grains. Large quantities of Hazel pollen occur as a fine yellow mist at springtime in parts of Europe, and may contribute to attacks of hay fever (allergic rhinitis). Magnification: x1, 730 at 5x7cm size

© POWER AND SYRED/SCIENCE PHOTO LIBRARY

Hen flea

Hen flea. Coloured scanning electron micrograph (SEM) of a hen flea (Ceratophyllus gallinae). This flea is a parasite on dry nesting birds, such as the blue tit and chickens. The head (upper right) is helmet-shaped and the body is laterally flattened, adaptions which allow easy movement through the feathers of the host. The antennae can be withdrawn into grooves on the side of the head. The mandibles with long palps are modified for the blood sucking habit of this insect. Most fleas remain on the host only while feeding. This flea also occupies the nest of the bird. Magnification: x30 at 5x7cm size

© POWER AND SYRED/SCIENCE PHOTO LIBRARY