220 LECTURE V. 



ties ; and his friends must have suppHed 

 him with the terms which he employs, 

 Monocoiha, DicoiKa, Tricoiha, and Tetra- 

 coilia. He considers the heart as a pump, 

 which forcibly impels the fluid it contains 

 into the vessels. Where there are two ca- 

 vities, he says, one is an auricle, and the 

 other a ventricle. The auricle is a cistern or 

 reservoir, from which the contents are sud- 

 denly forced into the more efficient cavity 

 or pump. Sometimes there is a heart or 

 pump to the pulmonary circulation, and 

 none to the corporeal; and sometimes there 

 is one for the latter and not for the former, 

 and sometimes one for each. Even in the 

 quadruped and bird, in which the heart 

 appears most complex, he says, it is equally 

 simple, there is a heart for either circula- 

 tion, but these are united into one organ. 



In advocating Mr. Hunter's reputation 

 as a general physiologist, I ought not to 

 omit to commemorate his labours in exa- 

 mining the circulation of the blood in the 

 higher classes of animals. Doubtless the 



