1018 MR. L. R. CRAWSHAY ON THE ARTERIAL [Dec. 11, 



A. gastrica dextra. — A varying number of vessels were given 

 ofl' from this artery to the pancreas and adjacent structures as 

 follows: — In Bibfo horeas one, some distance beyond the ^. hejxttica; 

 in B, mauritanicus one, from near the stomach ; in R. hexadactyla 

 one ; in R. esculenta two, opposite the origin of the hepatica ; 

 in R. clamata (two specimens) one, in the same position ; in 

 R. iigrina two. 



(In addition to these vessels, the pancreas also received a single 

 vessel from before the origin of the hepatica in R. esculenta, 

 R. hexadactyla, and R. tigrina.) 



The specimen of R. cateshiana (text-fig. 146, p. 101 7) was remark- 

 able for the fact that after the sepaiation of the gasti'ica sinistra, 

 three arteries were shortly given off to the pancreas and then the 

 remainder of the A. cosliaca went to the liver and gall-bladder, the 

 gastrica dextra being entirely absent. It is conceivable that this 

 abnormality might be correlated with the anastomosis which so 

 frequently occurs on the right side of the pylorus between the 

 normally present gastrica dextra and the duodenal branch of 

 the Tnesenterica. In this case, moreover, the latter artery was 

 continued without diminishing in size over the pylorus and up 

 the right side of the stomach ; in fact over the region which the 

 A. gastrica dextra would normally traverse. In this individual, a 

 male, which was sent to me alive from America, the constricted 

 pyloric region was extremely long. In another, a large female of 

 the same species which was examined for comparison, the condition 

 of the arteries here was quite normal, and in this latter case the 

 constricted pyloric region was very short. 



In the other species, the A . gastrica dextra was continued as a 

 rather larger vessel than the A. hepatica to the right side of the 

 stomach and towards its more distal portion. In three individuals 

 of R. temporaria it only varied in the relative points of its division. 

 It divided into two branches at about two-thirds of the way to 

 the stomach, and each branch again divided into two near the 

 latter. 



In R. esculenta, the first division of the A. gastrica dextra took 

 place closer to the stomach and the posterior branch was continued 

 as a compact vessel down to the pylorus. In R. tigrina, it began 

 to divide about halfway to the stomach, which it reached in three 

 or four branches. In R. clamata and R. hexadactyla, it divided 

 into an anterior and posterior branch on or near the surface of 

 the stomach (text-fig. 145, p. 1015 ; text-fig. 147, p. 1019). Bufo 

 inauritanicios somewhat resembled R. tigrina, but the subdivision 

 of the artery was more distal. B. horeas was very distinct from 

 the rest by the simultaneous division of the artery close to the 

 stomach into five equal-sized branches, the posterior branch 

 running back as usual to the pylorus, the others breaking up at 

 short intervals in front of it (text-fig. 153, p. 1029). 



A. mese^iterica anterior. — The extent of variation in this artery 

 is so great that it is difiicult to draw more than very general 

 comparisons between the species under consideration. 



