205 



appears , however , to have had chiefly in mind the question whether 

 or not the artery formed a loop around the nerve and if so to what 

 degree is surrounded it. It is not quite clear, therefore, in how many 

 of his cases the artery passed before or behind the nerve. In 31 

 instances , 10 right and 21 left there was no loop. In 41 cases 19 

 right and 21 left the loop was made by the ramus perforans 

 (a branch of the upper division of the inferior thyroid). This shows 

 that in 72 of 112 cases no loop was formed by the main artery. In 

 the remaining 40 cases, 27 right and 13 left, the loop was almost or 

 quite complete. 



Had I been acquainted earlier with Kocher's views I should have 

 paid particular attention to this point; as it is I have endeavored 

 simply to determine whether the artery passed before or behind the 

 nerve, and have disregarded the relations of small branches. 52 bo- 

 dies were examined on both sides and 27 on one side. Of the 52 

 the arrangement was symmetrical in 29 and the sides differed in 23. 

 Of the 29 cases the artery was before the nerve on both sides in 21 

 and behind it in 8. Of the 23 unsymmetrical bodies 17 had the ar- 

 tery behind the nerve on the right and before it on the left; 3 had 

 the artery before the nerve on the right and behind it on the left. 

 The artery was absent or so small as not to reach the thyroid in 3, 

 2 left and 1 right. On the opposite side of each of these three cases 

 the artery was before the nerve. 



In 27 bodies only one side was examined. On the right the 

 artery was before the nerve 7 times and behind it 6. On the left 

 the artery was before the nerve 10 times and behind it 4. 



Adding these observations together we find that on the right 

 the artery was before the nerve 33 times and behind it 31. On the 

 left the artery was before the nerve 49 times and behind it 15. 

 Three times the artery was absent or very small. It appears, there- 

 fore, that as far as we can judge from so small a series, it is equally 

 probable that the right nerve or artery will be in front, and that on 

 the left the chances are three to one that the nerve will be behind. 



This series tends to support the practical deduction that has 

 already been made that when it is necessary to tie the artery near 

 the gland the vessel should be carefully isolated. 



