Abstract
The vascular system in the rat lower incisor and the process of its development were examined in cleared specimens of various ages of postnatal growth, and the following results were obtained. Arteries leading to the lower incisor come chiefly from the lingual side and connect with a regular capillary network lying buried in the external surface of the outer enamel epithelium. The capillaries flow together along the lateral border of the enarr el organ, to join a rich venous plexus surrounding the incisor bud. The efferent veins arising from the plexus connect with the pterygoid plexus and anterior facial vein. With the progress of postnatal growth, the capillary network in the outer enamel epithelium comes to show a distinct regularity, while the venous plexus surrounding the capillaries from the outside extends widely to enclose the enamel organ and the posterior two-thirds of the incisor. In addition to these descriptions, some discussions are made on the functional significance of the capillary network and the venous plexus.
