URSUS. 91 



Of a Bear \Ursus arctos and U. americanus 1 '] . 



The trunk is that of a quadruped ; but the extremities come nearer 

 the human, and more so to the whole four feet. They have no clavicles, 

 although many of their actions are such as would incline us to believe 

 that those bones would be necessary ; but these actions are not so ex- 

 tensive as to require such projectors. 



The oesophagus is pretty small in its beginning, but becomes larger 

 and larger down to the diaphragm, where it is again contracted to the 

 size of a common finger : the largest part is in the thorax, and is nearly 

 as large as the thick of one's arm : at this part it is smooth on the 

 inside and not strong ; but this enlargement was probably accidental 

 or from disease. As soon as the oesophagus passes through the dia- 

 phragm, it dilates into the stomach, which is nearly the shape of the 

 human stomach, but is very strong in its coats : it has nearly the same 

 situation [as in the human subject]. The duodenum passes to the right, 

 then down, and from that to the left behind the root of the mesentery. 

 The intestines are one continued canal from the pylorus to the anus, so 

 that there is no caecum or colon. The intestines have no valvulse con- 

 niventes 2 , and are not so firmly fixed by mesentery as [are] the human. 

 At the sides of the anus there are two bags, one on each side. They are 

 very small ; their ducts or openings are just at the verge of the anus 3 . 



The lungs on the right side are larger than those on the left, and are 

 divided into three lobes ; on the left side into two only. The trachea 

 is large ; the cartilages are pretty thick at their fore-parts or middle, 

 and become thinner backwards towards their ends, where they termi- 

 nate in a thin edge. Their disposition and union are in alternate pairs ; 

 the upper and lower edges of every other one, at the fore-part, overlap 

 the edges of the others ; but at their posterior ends they are overlapped 

 by those which were overlapped in their middle ; their posterior ends 

 come very near one another, and can easily be squeezed one over the 

 other. The bear has a pulmo-azygos 4 . 



The liquor pericardii was slimy like synovia : whether this arose 

 from disease or not, I cannot possibly say. 



The liver is divided into three lobes, with the lobulus Spigelii. The 

 gall-bladder has three hepatic ducts : the ductus communis enters with 



1 [In the next dissection Hunter refers to the anatomy of both the ' Russian ' and 

 'American ' bears. The skull of an American black bear ( Ursus americanus) is No. 

 4015, Osteol. Series.] 



2 [Hunt. Preps. Nos. 698, 699, 700.] 3 [Home, Comp. Anat. i. p. 430.] 



* [The ' azygous ' lobule of the lung, interposed between the heart and diaphragm, 

 may here be meant.] 



