IC) PSYCHOLOGY. 



tively. Tlie segment governing tlie arms is especially 

 active, in male frogs, in the breeding season; and these mem- 

 bers alone with the breast and back appertaining to them, 

 ever3'thing else being cnt away, will then actively grasp a 

 finger placed between them and remain hanging to it for a 

 considerable time. 



The spinal cord in other animals has analogous powers. 

 Even in man it makes movements of defence. Paraplegics 

 draw up their legs when tickled ; and Robin, on tickling 

 the breast of a criminal an hour after decaj)itation, saw the 

 arm and hand move towards the spot. Of the lower func- 

 tions of the mammalian cord, studied so ably by Goltz and 

 others, this is not the place to speak. 



If, in a second animal, the cut be made just behind the 

 optic lobes so that the cerebellum and medulla oblongata 

 remain attached to the cord, then swallowing, breathing, 

 crawling, and a rather enfeebled jumping and swimming 

 are added to the movements previously observed.* There 

 are other reflexes too. The animal, thrown on his back, 

 immediately turns over to his belly. Placed in a shallow 

 bowl, which is floated on water and made to rotate, he re- 

 sponds to the rotation by first turning his head and then 

 waltzing around with his entire body, in the opposite direc- 

 tion to the whirling of the bowl. If his support be tilted so 

 that his head points downwards, he points it up ; he points 

 it down if it be pointed upwards, to the right if it be 

 pointed to the left, etc. But his reactions do not go 

 farther than these movements of the head. He will not, 

 like frogs whose thalami are preserved, climb up a board 

 if the latter be tilted, but will slide off it to the ground. 



If the cut be made on another frog between the tha- 

 lami and the optic lobes, the locomotion both on land 

 and water becomes quite normal, and, in addition to the 

 reflexes already shown by the lower centres, he croaks 

 regularly whenever he is pinched under the arms. He 

 compensates rotations, etc., by movements of the head, and 

 turns over from his back ; but still drops off his tilted 



* It should be said that this particular cut commonly proves fatal. The 

 text refers to the rare cases which survive. 



