366 MU. F. E. BEDDARD ON THE [Feb. 16, 



Tlie adrenal jjortal vessels are more numerous than those of the 

 right adrenal body. The anterior, made by the union of two 

 main branches, each of which recovers blood from three inter- 

 costal spaces, enters the adrenal body in front of the anterior 

 spermatic artery ; the second, gathering blood from three inter- 

 costal intervals, lies between the two spermatic arteries. 



Renal Arteries. — In noting the most important fact about the 

 renal arteries, namely, that there is only one to each kidney, it 

 must be borne in mind that the kidneys are extraordinarily 

 small. They measure about 2^ inches in length, and the posterior 

 is situated a foot away from the vent. Each renal artery 

 enters the kidney at its anterior end, and between the two renal 

 arteries arises the inferior mesenteric, which is much more 

 important than any of the slender intestinal artei'ies which 

 follow. 



Lachesis geamineus. 



The anterior vertebral is short in this species, only reaching to 

 a point 1| inches from the heart (and 6 inches from the snout) 

 before plunging into the parietes. It gives off but a single inter- 

 costal branch, which is not far from its origin. The right aortic 

 arch itself is much more slender than the left ; it gives ofi' two 

 intercostal arteries before joining the left aorta. The dispropor- 

 tion between the right and left aorta is so very marked that the 

 former when it joins the latter is not larger than one of the 

 intercostals. After the junction of the aortte to the posterior end 

 .of the trunk there axe only 22 intercostals ; as is the rule, they 

 become more numerous posteriorly. For example, the region 

 lying between the junction of the aortse and the origin of the 

 superior mesenteric only gives off six of these arteries. Another 

 peculiarity of this species is the fact that all the intercostal 

 arteries, without a single exception, enter the parietes in the 

 middle line. This is associated with, though it can hardly be 

 caused by, two particularly projecting bands of muscle which lie 

 one on either side of the dorsal median line. That the strong 

 development of these muscular bands has no special relation to 

 the accurately median entrance of the intercostal arteries appears 

 to be shown by the relation to the same of the intercostal portal 

 veins. 



Intercostal Veins. — There are six of these veins in front of the 

 point of origin of the superior mesenteric artery ; but they have 

 no special correspondence to the six intercostal arteries which 

 arise in the same area. All of these veins emerge from the 

 parietes to the left of the longitudinal bands of muscle referred to. 

 Just at the level of the superior mesenteric artery a stout portal 

 vein emerges from the right side ; thereafter follow two veins, 

 also emerging from the right side. The remainder of these 

 vessels (six in number) arise again on the left side of the dorsal 

 median line. 



The liver commences very high up in the body. Its apex is 



