_ ANATOMY OF THE OPHIDIA: 383 
193; XLV.-126; XLVE-128; XLVII-129; XLVIEL-131,; 
NID LISS = ID NEGe IMLS e JIN sie INDE AUT 
WAGs TN TS) S TUL = WIS ENT VG 
153; LX—-156. . 
The courses of the intercostals vary slightly in different parts of 
the body. All but the last, LX.—156, enter the parieties anterior 
to their points of origin. ‘Anteriorly the difference is only a 
millimetre or so; at the posterior end of the liver it has in- 
ereased to an average of three to four millimetres, equivalent to 
the length of one vertebra. In the region of the kidneys each 
artery runs forward the distance of about two vertebr before 
entering the body-wall. These latter branches are crossed by the 
renal arteries; the blood in the intercostal arteries flowing 
forward and in the renal arteries flowing backward. This 
arrangement is what might be expected to result from a 
lengthening of the body in this region. As the kidneys move to 
the rear the arteries entering them would be drawn out to the 
rear. As the dorsal aorta is drawn to the rear there is a tendency 
for the intercostal branches to maintain their former points of 
entrance ; to accomplish this necessitates that they course for- 
ward. A few are peculiar in the, following details :—I.-31 is the 
longest, measuring 11 mm. ; IL.-35 bifurecates, sending branches 
to the lung and cesophagus; III.-41, XX.-86, and XXI—-95 
bifurcate and send one fork to the lung: LVIII.-152 enters 
9-7 mm. to the left of the median line, and forks just before 
reaching the parieties; LIX.—153 enters a similar distance to the 
right ; LX.-156 is the only one that enters the parieties at the 
same level as its origin, all the others trending forward to a 
greater or lesser extent. 
The gastric artery is at the level of the 81st g.; upon reaching 
the stomach it bifurcates into anterior and posterior branches, 
the latter a trifle larger. There are three mesenteric arteries : 
1-119; 11.99; I1I1.-108. There are ten intestinal, rectal, and 
cloacal arteries; 1-113 is 32 mm. long; II.-119; II1.-129; 
VAIS OE MVE aS Ore Wale 4 5) Velie ol Wel 52 5 xe 153; 
X.-155; the majority of these are long straight vessels. 
There are four renal arteries on the right and seven on the left 
side. The right kidney extends from the 116th to the 139th g., 
and its four arteries leave the aorta as follows :—I.-118 ; I1.-126 ; 
TI1.-129; IV.-135. All of these enter the organ posterior to 
their origin. No. I. is the largest; at the kidney it divides into 
an anterior branch which forks to supply the kidney and the 
ovary, and a posterior branch to the kidney alone. The left 
kidney extends from the 125th to the 145th g., and is practically 
the same size as its mate. The seven arteries leave the aorta 
Aeifollows et 122—) 11 IAT Vesa VE 39 5 
VI.-141; VII.-143. No. I. is the largest and forks to supply 
the ovary. Nos. I. to VI. are quite oblique; Nos. V. to Vil. 
enter the kidney almost directly. 
