The arterial system of a pig embryo

TypescriptM.A. University of Missouri 1918This paper is one of a series describing the anatomy of a pig embryo of about 20 mm. in length, which work was undertaken several years ago in the Department of Anatomy of The University of Missouri under the supervision of Dr. Franklin P. Johnson. For the present work, pig embryo No. 1.23 of the Missouri Embryological collection, was used, which measured 21.6 mm. before sectioning. It was fixed in Zenkers solution, cut in transverse sections ten microns in thickness and stained with alum cochineal and orange G. In securing the proper data for the complete description of the 20 mm. pig embryo, several methods were used. Graphic reconstructions of the whole arterial system were made, which have served as a basis for the present description. Wax models were also made when it was deemed necessary to show views of certain vessels in their third dimensions. For the most part the reconstructions have been compared with the dissections of post-natal pigs of only a few days old, the arterial systems of which are virtually the same as in the adult