292 



THE BEHAVIOUR OF HYLA AUREA TO STRYCHNINE. 



By H. G. Chapman, M.D., B.S., Demonstrator of Physiology 

 in the University of Sydney. 



(From the Physiological Laboratory of the University of Sydney.) 



It has been noted not infrequently that the common Australian 

 frog, Hyla aurea, is much less susceptible to the poisonous alka- 

 loid strychnine than the European frog of the genus Rana. 



This diminished susceptibility or increased resistance can be 

 most easily shown by a determination of the minimal lethal dose 

 of strychnine for Hyla. The minimal lethal dose for various 

 species of Rana has been measured by various observers. There 

 seems to be a general agreement that this lies between 2 mg. and 

 5-5 mg. per kilogram of body-weight. Falck* found that to kill 

 a frog with strychnine nitrate at least 2 mg. per kilo must be 

 injected. Sollman,f working in America, gives 5*5 mg. per kilo, 

 as the lethal dose for the frog. 



* Volkmann's Sammlung Klinischer Vortrage, No. 69. 

 T Text-Book of Pharmacology, Philadelphia, 1901, p. 171. 



