Embryological study on the caecum and colon of horses

Abstract

1) 3.0cm horse embryo has the single layered colon, as in the case of the carnibora and mankind. In 3.2cm embryo, the colon changes into the double layered colon, forming the pelvic flexure.
2) The great intestine of horse embryo also shows the tendency to make the coiled colon, after the formation of the double layered colon, as in the case of cattle and swine. We call this portion the "Vertex of flexure" (b of Fig. 5B), which is the small flexure succeeding to the pelvic, flexure (a of Fig. 5B).
3) The translocation of the caecum and colon of horses from the right abdominal wall to the left is due to changes of food after the birth, which causes the great expansion of the great intestine.
4) We reguest attention to the great mistake about the position of the ostiums of ilium and colon in the horse's caecum, hitherto described in some famous text-books on the anatomy of the domestic animals, for example that of ELLENBERGER-BAUM (15th, 1921, and 16th, 1926, editions).
This error, however, was corrected in the later edtion (17th, 1932, edition).