Foetal tooth. Coloured light micrograph (LM) of a section through of 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 (orange), with a layer of dentine (cyan) beneath this. The larg pale region below these is the pulp. A layer of ameloblasts (purple) forming the enamel, and odontoblasts (brown) forming the dentine, are present. Bone of the jaw is seen at the left of the image. Magnification: x 40MB when printed 10cm tall.