Embryonal and fetal development of capillaries: microangiographic investigations. II. The telencephalon.

The development of the intracerebral capillaries of the telencephalon was studied by the combined techniques of microangiography and histology in embryos and fetuses of cattle and pigs. In the telencephalic colliculi ganglionares, vascularization starts during the 4th week of gestation and leads to the formation of a peripheral and a central arterial system separated by the internal capsule. Capillary development within the pallium occurs 3 weeks later and consists in the formation of longitudinal arteries, concentrically arranged rings of deviations and bifurcations, and a periventricular capillary network.