1016 • MR. L. E. CRAWSHAY ON THE ARTERIAL [DeC. 11, 



A. gastrica sinistra. — This artery is liable to considerable 

 variation, even in individuals of the same species. In this 

 I'Bspect, three specimens of E. temporaria were all different. 

 Here, from two to four vessels were given off to the cai-diac 

 region of the stomach, sometimes dividing before reaching it. 

 The direction of the main trunk was always towards the median 

 point, about which the artery then either simply bifurcated, or 

 further subdivided while in the omentum, the posterior branch 

 in either case running down the left wall of the stomach to the 

 pylorus. 



Within the limits of this variation, R. damata., R. hexadactyla, 

 and R. esculenta scarcely differed from R. temporaria. R. tigrina 

 showed a greater tendency to division in the omentum, the artery 

 simj)ly giving off five or six subequal bi'anches in a more or less 

 i-egular series, the last of which became attached to the stomach 

 not far in front of the pylorus. In this species, the first gastric 

 vessel was given off from the A. cceliaca before the origin of the 

 A. gastrica sinistra. 



In R. cateshiana, three minute vessels were first given off 

 anteriorly to supply the omentum, then a single branch to the 

 cardiac region of the stomach, the remainder to the very long 

 pyloric region (in this individual), reaching it in five vessels, of 

 which the last ran down as usual to the pylorus. 



In Bnfo horeas and B. mauritanicus, the first gastric vessel was 

 given off before the origin of the A. gastrica sinistra. The latter 

 artery then very shortly gave off a single gastric vessel and 

 afterwards divided into two branches, which at once became 

 attached to the stomach near its median point and continued to 

 break up over its substance, the posterior branch following the 

 usual course to the pylorus. There was therefore very little 

 tendency here to early division in the omentum, as also was the 

 case in R. hexadactyla. 



In both specimens of R. clamata two or three branches of this 

 artery went to the right side of the stomach. In all other cases 

 it was almost entirely distiibuted to the left side. 



There is no mention made by Gaupp of branches from the 

 A. gastrica sinistra supplying the pancreas. The artery, however, 

 commonly sends back one or more small branches to that gland, 

 which vary in number and position. In R. temporaria there were 

 two in two individuals and three in a third. In R. esculenta one, 

 near the origin of the artery and some way befoi'e the first gastric 

 vessel. In R. catesbiana two before the first gastric vessel and a 

 third distally. In R. clamata four in one individual. In R. tigrina 

 five. In R. hexadactyla one after the first gastric vessel sending 

 . a branch backwards to the pancreas and then following the bile- 

 duct &c. nearly to the liver, also three small ones. In Rufo bot'-eas 

 and B. mauritanicus three ; in the latter species rather close 

 together and from the distal portion of the artery (text-figs. 145, 

 146, 147, 153). 



A. hepatica. — This artery was in all cases given off not far 



