360 MR. F. E. BEDDARD ON THE [Feb. 16, 



corresponding exactly to the number of vertebrae, and shoAv but 

 the faintest traces of commencing disappearance. That is to say, 

 the arteries are of fair size and equisized ; in only one case did I 

 observe an artery reduced to thread-like dimensions. Further- 

 more, the arteries are accurately median at the points where they 

 enter the parietes, and the foramina through which they enter 

 are larger than the ai-teries themselves. 



Intercostal Arteries. — These arteries commence to arise from the 

 right aoi'tic arch before its union with the left. But in this 

 region they do not forra a continuous series ; there were only 

 three. After the junction of the two aortse the intercostal arteries 

 still retain the median point of entrance into the parietes, a 

 position which distinguishes them at once from the intercostal 

 veins — as also in Lachesis gramineus. The arteries are very 

 numerous, and there are occasional stretches of ten or a dozen 

 which ai-e continuously at regular intervals. In a very few 

 cases the ai'teries are so excessively slender as to suggest com- 

 mencing disappearance. I coxmted altogether 94 of these arteries, 

 to which I think 3 or possibly 4 are to be added. The total is 

 only just under the 100. As may be inferred from their median 

 position, none of these arteries are paired ; nor can an anterior 

 series be distinguished from a posterioi', save that the first few 

 are rather fai'ther apart than they become later. 



Intercostal Ported Veins. — These veins are, as is usual, few in 

 number when compared with the intercostal arteries. I counted 

 altogether 13 of them, of which the anterior 6 are less important 

 than those which foUow. The first 6 lie ojaposite to the liver, 

 and are therefore not direct affluents of the main trunk of the 

 portal vein. The first arises after the 7th intei-costal ai'tery * ; 

 the next 5 ai'e separated by fewer intei'costal arterial trunks. 

 These first 6 veins spring from the body-wall to the left of the 

 median dorsal line. The 5 following intercostal jaoitals spring 

 from the right side of the dorsal middle line. The first of this 

 series, i. e. the 7th of the entire series, is a little beyond the end 

 of the liver. The next two, close together, accompany the pos- 

 terior gastric artery ; the 10th in a similar way accompanies the 

 superior mesenteric, while the 11th and 12th correspond respec- 

 tively to the testicular arteries. The latter vein and the 13th, 

 which is in the kidney-region, emerge from the body- wall on the 

 left side of the dorsal median line. It will be noticed that some 

 of these veins spring from the middle line of the parietes. 



The spermatic artery which supplies the anterior testis is a single 

 vessel which enters the gonad near to its posterior end. It there 

 becomes longitudinal and i-uns forwai-ds as well as backwards 

 along the vas deferens. It is the first ai-tery for the supply of the 

 viscera which is given ofi" by the aorta after the supeiior mesen- 

 teric. This longitudinal testicular trunk gives oflF one bi'anch 

 anteriorly and two bi-anches posteiiorly to its origin from the 



* Counting from tlic junction of tlic right and ki'l aorta". 



