Images Dated 31st October 2006

Blood cells

Blood cells, computer artwork. Red blood cells (red), or erythrocytes, are biconcave disc-shaped cells that are responsible for supplying tissues with oxygen. They are about 7 micrometres in diameter. They are the most abundant type of cell in the blood. White blood cells (grey and multicoloured), come in several varieties and sizes according to their function. Shown are small lymphocytes, which play an important role in the immune system. They have knobbly protrusions or microvilli on their surfaces

© PASIEKA/SCIENCE PHOTO LIBRARY

Sheep tick, SEM

Sheep tick. Coloured scanning electron micrograph (SEM) of a sheep tick (Ixodes ricinus). The tick's mouthparts are between its two front legs. This arachnid is the principal vector of Lyme disease, which is caused by the bacterium Borrelia burgdorferi, in Europe. It is common in the damp underbrush of European woods and attacks various domestic and wild animals, including dogs and humans. Lyme disease causes skin lesions, neurological and cardiac abnormalities, and recurrent arthritis

© STEVE GSCHMEISSNER/SCIENCE PHOTO LIBRARY

A Unwelcome customer, 1772. Artist: Caldwell

A Unwelcome customer, 1772. A bull bursts into a shop, shocking the lady customers who drop the samples of lace they were looking at. The bull has a fur muff on one horn. Illustration from Social Caricature in the Eighteenth Century ... With over two hundred illustrations by George Paston (pseudonym of Emily Morse Symonds], (London, 1905)

© The Print Collector / Heritage-Images