FiTCHETT. — Physiological Action of Tutin. 299 



shows almost constant movement, either clonic spasms or running-move- 

 ments, chiefly of the fore paws, until exhausted. Urination occurs during 

 the convulsions, but, of course, vomiting was not observed. The animal 

 utters no cry, and indicates in no way that it suffers pain. In the later 

 stages it is comatose, and usually dies from exhaustion. 



(c.) Action on Guinea-pigs. 



No series of experiments was made to determine the minimum lethal 

 dose in these animals, but it would appear to be rather smaller than in 

 rabbits. A dose of 2 mlgm. per kilo caused symptoms in thirty minutes 

 and death in seventy minutes in one case (Exp. 11), while a dose of 1 mlgm. 

 per kilo caused convulsions, but the animal recovered (Exp. 167). 



A young guinea-pig was killed by a dose of 1 mlgm. per kilo, while another 

 •of the same age (five days) showed symptoms with 0'75 mlgm. per kilo, 

 but recovered. It would appear from this that the young guinea-pig is 

 more easily affected than the adult. 



By oral administration a dose of 1*5 mlgm. per kilo was insufficient to 

 produce obvious symptoms, but a dose of 2 mlgm. per kilo repeated in 

 forty-eight hours caused death (Exp. 13). 



The symptoms are very like those shown by rabbits — viz., unnatural 

 attitudes, rapid breathing, twitching, general convulsions, and running 

 movements of the limbs. The spasms are more clonic than tonic. When 

 convulsions first appear, the animal tumbles and tosses about in every direc- 

 tion, but soon takes up a position on its side, and then continues in constant 

 inovement until exhausted (Exps. 14, 167). 



2. Action on Birds. 



It is the common opinion that birds are immune to the tutu-poison. 

 It were not strange did a relative immunity exist, for the plump, sweet, 

 attractive-looking berries seem to have been designed by nature for the 

 especial purpose of inducing birds to eat ; and that they do eat them freely 

 and without injurious effect is certain. Mr. Maning, author of " Old New 

 Zealand," quoted by Lauder Lindsay (3), says, " Many kinds of birds live 

 entirely on the tutu-berries when in season. . . . The tui {Prosthemadera 

 novce-zealandice) I have kept tame and fed for months on nothing else." 



Again, birds differ from mammals in having a higher rate of oxidation, 

 a higher temperature, and a peculiar metabolism, which results in the 

 excretion of urates instead of urea in the urine — features which might 

 conceivably have an important bearing on the question of their possible 

 immunity. 



Christie (11), as the result of experiment, inclined to the general opinion 

 that birds are immune. He injected in all 40 minims of an ethereal solution 

 of " oil of tutu " into the " chest cavity " of a young rooster. Beyond 

 some slight symptoms which were attributed to the ether, and a marked 

 increase in the frequency of defsecation, no characteristic effect was noted. 

 He observes that " there was no twitching, although the dose (40 m.) is 

 twice as much as is necessary to convulse a cat " ; and concluded that the 

 bowels are chiefly affected in birds, and that, therefore, they are saved by 

 rapid excretion by this channel. When the above statement is more closely 

 examined it is found that Christie administered probably not more than 

 1 mlgm. of pure tutin per kilo. The symptoms were wanting because the 

 dose was inadequate. 



