HMS Beagle Ship laid up Darwin's Voyage
"Beagle laid ashore, River Santa Cruz". Copperplate engraving, art by Conrad Martens, engraved by T. Landseer. Published by H. Colburn 1838. Plate from 'The Narrative of the Surveying Voyages of HMS Adventure and Beagle'. The Beagle was grounded for repairs on the 16th April 1834 to repair damage caused by a rock at Port Desire and to check the copper sheets were in tact (Fitzroy notes they were about to enter the Pacific where worms soon eat their way through unprotected planks). They found that a piece of the false keel had been knocked off and the copper was heavily rubbed in places. The carpenter Mr. May repaired it all in one tide. The Beagle undertook a repainting and refit while Fitzroy, Darwin and a small crew explored several days upriver.
© PAUL D STEWART/SCIENCE PHOTO LIBRARY
Prehistoric marine life of around 380 to 360 million years ago showing three carnivorous species
Prehistoric marine life of around 380 to 360 million years ago showing three carnivorous species (Dunkleosteus, Stethacanthus, Cladoselache spp.). Dunkleosteus, the largest, dark grey fish, measured up to 10 m. The Stethacanthus shark had an anvil-shaped dorsal fin, and Cladoselache at upper right was another shark, sleek and swift, resembling the present-day mackerel sharks.
Common horsetail spore, SEM
Common horsetail spore. Coloured scanning electron micrograph (SEM) of a spore of a common horsetail (Equisetum arvense) plant. The spore (green) bears elaters (grey) that expand and contract with changes in humidity. Elaters help to tangle spores together into a clump called a propagule, and to dig spores into the soil. A spore is part of the sexual reproduction of this plant, and horsetails normally use asexual reproduction using rhizomes (underground stems). Horsetails are the only living group of a primitive family of plants, the Sphenopsids, that date back to the Devonian period, 355-410 million years ago. Magnification: x555 at 6x7cm size.
© POWER AND SYRED/SCIENCE PHOTO LIBRARY