The morphogenesis of the vascular elements in the fetal external ear of 37 swine fetuses (German landrace), from 90-330 mm crown to-rump length, was described.
A simple pattern for the auricular vascular supply in the form of 5-7 arterial branches and two large veins could be recognized in fetuses ranging from 90-100 mm CVR length.
In 150-200 mm length fetuses, the blood vessels were differentiated into a definite pattern of construction and were accompanied by satellite veins on both sides.
The third stage of development showed a progressed pattern of distribution as the arteries presented further regional differentiation along their course, and the veins were connected transversely with several venous arches.