Foetal tooth. Coloured light micrograph showing an unerupted foetal tooth. The first set of teeth begin to develop around six weeks after conception. The permanent teeth begin to develop around a month after this. The foetal tooth is capped with a layer of enamel (red), with a layer of dentine (pink) beneath this. The pale region below these is the pulp. A layer of tissue above the enamel (purple, top) is made up of epithelial cells. Magnification: x160 when printed 10cm tall.