and Structure of the Proteus Angutnus. 5 



mander, the lateral movements of the trunk will be still more 

 limited than in the proteus, by reason that the ridge, formed 

 by the canal of the spinal cord, will impede the free motion of 

 the articular processes on one another. We have observed at- 

 tentively, continue the authors, and compared the movements 

 and mode of progression of the proteus, and of the salamander 

 and its larva, both in water and out of it ; and have had the 

 satisfaction of seeing that these movements, as well in swimming 

 as in walking, correspond with the consequences previously de- 

 duced from a simple examination of the skeleton. A few of 

 these observations they then proceed to relate. 



The protei which, with this view, they submitted to observa- 

 tion, had already lived many months in earthen vessels, the 

 bottoms of which were flat and of the figure of a parallelogram. 

 To these vessels were adapted lids formed of many pieces ; but 

 so fitted together that the light was unable to penetrate, and 

 the animals consequently lived always in complete darkness. 

 When it became necessary to change the water, a portion of 

 the lid was removed, and then the animal, by moving to the 

 opposite side of the vessel, was able to continue in obscurity. 



It has been already observed, that the proteus, in ordinary 

 circumstances, remains as if immoveable at the bottom of the 

 vessel ; but at once begins to move with more or less rapidity 

 as the light is let in upon him. Of this fact, the authors availed 

 themselves in their observations on the movements of these ani- 

 mals. Having first discovered in what part of the vessel the 

 animal reposed, the piece of lid above him was gently raised, so 

 as to expose him to light. As soon as he felt its influence, he 

 instantly began to move and withdraw himself to that part of 

 the vessel which was still dark. In making this movement, 

 however, he did not always employ the same kind of motion. 

 Sometimes he drew up the lower part of the trunk and the tail, 

 or rather gathered himself up in the manner of a serpent. In 

 doing this, he made use only of the muscles of the spine, and 

 not of those of the hind limbs, which, during this action, re- 

 mained quite at ease, and followed tl>o trunk as if they had been 

 paralytic. When the body was thus gathered up, and formed 

 into a serpentine line, the animal thrust the hind limbs to the 

 bottom of the vessel; then stretching forward the whole trunk, 



