Power Penis

In an old building along London’s Harrow Road you find the Science Photo Library and a collection of hand-coloured scanning electron microscope photographs.

One set of pictures is of a pair of bean weevils (Callosobruchus maculatus) mating.

z3300303-weevil_penis-lr_1      z3300306-weevils_mating_crop-mr_1-1

The male’s penis has a tip covered in hard sclerotised spines, which unfold during copulation. These penetrate the lining of the female’s genital tract, leaving puncture wounds. In response, the female kicks off the male to end the copulation. Nevertheless, mating is costly for the female for if she copulates with more than one male she incurs extensive damage and so dies early. (HS Crudgington & MT Siva-Jotley, Nature 407, 17 October 2000 855-6.)

This three-dimensional world at a microscopic scale is limited by the demands of technology. That’s because the scanning electron microscope needs specimens to be in a vacuum and builds colourless images of electrons.

Carl Zeiss Launches Next-generation Analytical Electron Microscope  scanning-elecron-microscope-illustration

The weevil pictures are the work of C Power and A Syred at http://www.sciencephoto.com, the subject of a recent project by C Barras for BBC Earth.