LECTURE VII. 15 



The Tortoise seems more tenacious of the 

 vital principle than any other of the Amphibia. 

 Redi informs us, that in making some experiments 

 on vital motion, he, in the beginning of Novem- 

 ber, took a land tortoise, and made a large 

 opening in its skull, and drew out all the brain, 

 washing the cavity, so as to leave not the smallest 

 part remaining, and then, leaving the hole open, 

 set the animal at liberty. Notwithstanding this 

 treatment, the Tortoise marched away, without 

 seeming to have received the smallest injury: it 

 however closed its eyes, and never opened them 

 afterwards. In a short space the hole of the 

 skull was seen to close, and in about three days 

 there was a complete skin covering the wound; 

 and in this manner the animal lived, without the 

 brain, for six months, walking about, and moving 

 its limbs as before. Redi also cut off the head 

 of a Tortoise, which lived twenty-three days after- 

 wards ; and the head itself continued to snap the 

 jaws for more than a quarter of an hour after 

 its separation from the body. He repeated the 

 experiment of taking out the brain upon several 

 other Tortoises, both of land and fresh water; 

 all of which lived for a considerable space without 



