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Show 1 0 1 6 MR. L. R. CRAWSHAY ON THE ARTERIAL [D e c . 1 1 , A. gastrica sinistra.-This artery is liable to considerable variation, even in individuals of the same species. In this respect, three specimens of R. temporaria were all different. Here, from two to four vessels were given off to the cardiac 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. clamata, R. hexadactyla, and R. esculenta scarcely differed from R. temporaria. R. tigrina showed a greater tendency to division in the omentum, the artery simply giving off five or six subequal branches in a more or less regular 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. coeliaca before the origin of the A. gastrica sinistra. In R. catesbiana, 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 Bufo boreas 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 distributed 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 before 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 Bufo boreas 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 oft' not far |
