VENOMS OF THE TOAD AND SALAMANDER. 401 



the latter are proteid in nature (11). Both venoms have a 

 special action on the nerve centres. Gratiolet and Cloez 

 (8) found that 2 milligrams of the dried venom of the 

 toad when injected subcutaneously killed a greenfinch in 

 fifteen minutes with convulsions and loss of co-ordination. 

 Vulpian (12) and later Couty (13) observed that this venom 

 when placed in a subcutaneous wound was fatal to dogs 

 and guinea-pigs, but when administered by the mouth pro- 

 duced nothing more serious than vomiting, the fatal event 

 in the former case being preceded by excitement and 

 vomiting and sometimes by convulsions. Placed in con- 

 tact with the skin of frogs and tritons it is absorbed and 

 kills them in from two to three hours (14). 



Fornara (15) has shown that phrynin has an action on 

 the respiration and circulation very like digitalis, it induces 

 contraction of the arterioles and rise of blood pressure, 

 increased cardiac contraction and diuresis. According to 

 Phisalix and Bertrand ( 1 6) the blood of the toad is toxic 

 from the presence of some of the active principle phrynin ; 

 2 c.c. injected into a frog begins to produce symptoms 

 within five minutes, and in fifteen minutes the pupils are 

 contracted and hind legs paralysed, while 5 c.c. quickly kills 

 a guinea-pig. 



The venom of the salamander differs from that of the 

 toad physiologically by its predominant convulsive action 

 and by its inactivity on the heart. In the experiments of 

 Gratiolet and Cloez (8) small birds such as chaffinches 

 inoculated with it suffered from epileptiform convulsions, 

 and paralysis followed by death in from six to twenty-six 

 minutes ; but mice and guinea-pigs though severely affected 

 ultimately recovered. Vulpian (9) found that the venom 

 was fatal to dogs in from two to three hours, to guinea-pigs 

 in nine hours, and to frogs and toads in five hours. Its 

 action on frogs was studied by Roth (17): convulsive 

 movements are first induced, followed by paresis and 

 paralysis of all voluntary movements. The heart's action 

 remains normal for several hours after the cessation of all 

 voluntary and refiex action. 



Zalesky (10) observed that salamandrine produced 



