460 



Jackson^ s Anatomical Description 



I I 



rior-anterior part of the right side of the ventricle; are 

 situated one directly above the other and have a moder- 

 ately thick septum between them. The pulmonary artery 

 is the lowest of the three, and is quite as large as the two 

 aortas ; an inch and a half from its origin it divides into 

 two. The superior aorta, which is nearest to the auricular 

 opening, gives off branches, which are about as large as 

 itself, rather more than an inch from its origin. The other 

 aorta is considerably smaller than the last and gives off 

 no branch of any size till it reaches tlie abdominal organs ; 

 after supplying these, it unites with the continuation of 

 the superior aorta by a large branch about three inches in 

 length. Each of the three vessels has tw^o very deep, 

 semilunar valves. According to' Cuvler (Anat. Comp. 

 iv, 221), land tortoises have but a single origin for all the 

 arteries of the body, though the marine have two ; Dr. 

 Grant, however, found two aortas, commencing by sepa- 

 rate orifices from the ventricle, in the Testudo Indica. 



Of the Lungs very httle was noted. In the female 

 they extended fhe whole length of the upper shell, even 

 amongst the bones connected wath the extremities, filled 

 up the space on each side of the vertebral column, and 

 reached much more than half the way down to the union 

 of the two shells. Trachea fourteen inches and three 

 fourths of an inch wide ; rings perfect and of an oval 

 form ; in the male it was seventeen inches long and the 

 primary bronchi were eight inches. These last continued 

 in a straight line nearly or quite to the posterior extremity 

 of the lungs, but not receding far from the median line. 

 The secondary bronchi go off regularly on each side, 

 inclining backwards, small at their origin but immediately 

 becoramg of an immense size, measuring probably not 

 less than three or four inches transversely when cut open. 



