358 



Transactions. 



Exp. 155. 



The experiment was repeated with a second frog, pithed in the same way four hours 

 previously. The result was as follows : — 



Bight Foot. Left Foot. 



Frog B . . . . . . . . 6" 7" 



..10" 11" 



..8" 8" 



..8" 8" 



..8" 8" 



..8" 8" 



..8' 8" 



..8" 8" 



Average .. .. .. 8" 8-3' 



10 minims of a 0*l-per-cent. solution tutin was then injected under the skin of the 

 back, and after an interval of half an hour the reaction-time again tested. The time when 

 movement first took place only was noted. 



Twitched at 2" ; wthdrawn at 4" 



frog B . . . . . . . . . . . . 6" 



6" 

 6" 

 14" 

 14" 

 20" 

 16" 

 22" 

 14" 



Average . . . . . . . . . . 12-2" 



At 22 seconds there was a slight twitch, but no further movement took place, 

 although 70 seconds were counted. Pinching or pricking a foot met with an immediate 

 response, but the acid had no influence. Five minutes later no reflex movement could be 

 elicited by any means, and the heart could no longer be seen beating through the chest- 

 wall. 



Frog A was then tested again, and foimd to respond as actively as before. 



Exp. 156. 



A third frog, pithed one hovir previously, was treated in the same way. 



FrogC .. .. 10"\ 



5" 

 5" 



5" 

 5" 



5 y 



Right leg only withdrawn. Frog 

 removed from acid as soon as 

 first movement took place. 



Average . . 6" 



2 minims of a 0-5-per-cent. solution was then injected under the skin of the back, 

 and 10 minutes were allowed to elapse before the feet were dipped again. 



Frog C . . . . . . 6" \ 



.. sr 



.. 5" ' 



5" 



Both legs withdrawn. 



Average 

 1 minim of a 0'5-per-cent 

 FrogC 



solution tutin was then injected into the heart. 



5" 



6" 

 6" 

 6" 



Average 





