94 IOWA ACADEMY OF? SCIENCE Vol. XXVI, 1919 



In selecting rabbits for this investigation the matter of any 

 variation did not mark them as especially desirable, but of the 

 one hundred or more rabbits used in the laboratory, twenty were 

 selected because of their superior injection and these were used 

 for comparison in addition to the five especially prepared speci- 

 mens. > 

 THE PREDOMINANT ARRANGEMENT OF THE COELIAC BRANCHES 



While the relative number of variations are tabulated later in 

 this paper, I shall consider first that condition which is predom- 

 inant and may therefore be called the normal arrangement of the 

 coeliac branches. (Figure 7:1 and 2; Figure 8:3.) 



Where the abdominal aorta (AA) emerges through the diaphragm 

 it gives off the coeliac artery which extends toward the right to 

 the lesser curvature of the stomach. Figure 7:1 and 2. C.) The 

 following branches are given off from the coeliac artery. Between 

 7 and 9 mm. from the origin of the coeliac there arises the splenic 

 artery (S). About half way between the abdominal aorta and 

 the origin of the splenic artery there is given off, on the anterior 

 border of the coeliac, a small branch, the inferior phrenic artery 

 (P), which supplies the diaphragm. Bensley in his Practical 

 Anatomy of the Rabbit claims there are several inferior phrenic 

 branches, but in no case have I been able to locate more than one 

 vessel, which is very small. Quite frequently no vessel cor- 

 responding to the inferior phrenic was found arising from the 

 coeliac. It is quite possible that where the inferior phrenic 

 artery was not found this may have been the result of imperfect 

 injection, or, what is more probable, it may have arisen from 

 the abdominal aorta directly. While the latter is a very frequent 

 variation in the inferior phrenic in some animals, I wals unable to 

 identify it as coming off the aorta in the rabbit. The small size 

 of the vessel, however, may have precluded a proper injection. 

 While the inferior phrenic artery is shown in figure 7:2 and 8:3 

 and 6, in which cases it was seen, it will not enter further into the 

 discussion in this paper. Between 7 and 9 mm. from the origin 

 of the splenic artery the left gastric artery (LG) arises, figure 7:2. 

 The coeliac from this point continues as the Jiepatic artery (H) and 

 gives off, at the junction f)f the duodenum and the pylorus, the 

 gastroduodenal artery (GD). The hepatic artery continues through 

 the lesser omentum to the liver where it divides and supplies the 

 various lobes. 



The splenic artery arises from the ventral l^order of the citjliac, 

 curves to the right then to the left and then to the right again, 



