Angiogenesis (the formation of blood vessels) is essential for the growth and development of solid tumours. The following animation shows the results from a 3 dimensional simulation of the Angiogenesis model developed by Anderson and Chaplain, 1998, which is an implimentation of the discrete technique developed by Anderson et al. (1997). The sprouts initially form at the top of the figure and migrate, branching and anastomoses (forming loops) on their way to the tumour at the bottom of the figure. For more information on both discrete and continuous mathematical models of angiogenesis please consult this online article (http://www.maths.dundee.ac.uk/~sanderso/angiocont.htm)