LECTURE V. 209 



sidered as their lungs. Tliey are numerous 

 and distinct, situated all along the sides of 

 the animal in contact with the lateral blood- 

 vessels. These air-vesicles, or lungs of 

 worms, are exhibited by beautiful prepar- 

 ations in the Hunterian Collection ; and in 

 some instances, vesicles are also shown in 

 the back of the animal. , 



It is scarcely credible with what patience 

 Mr. Hunter examined the structure of the 

 lower kinds of animals. He contrived 

 spectacles with glasses of different degrees 

 of magnifying power, so that by a slight 

 alteration of the position of his head, he 

 could look through the one or the other^ 

 Mr. Clift tells me, he would stand for hours 

 motionless as a statue, except that with a 

 pair of forceps in either hand he was pick- 

 ing asunder the connecting fibres of the 

 vessels or parts, till he had unravelled 

 the whole structure. Thus did he make 

 the preparations of the amphinome flava, 

 and aphrodita aculeata, which you will find 

 in the Museum. In the former, he thought 

 he had distinctly traced numerous minute 



