VENOMS IN THE ANIMAL SERIES 323 



a way that showed that it was suffering acute pain. It was 

 unable to stand, and remained stretched out on the same spot 

 for a whole day, unable to get up, and completely stupefied. 



Interesting observations on the Heloderm have been made by 

 J. Van Denburgh and 0. B. Wight. The saliva of this lizard was 

 found to be highly toxic at certain times, and harmless at others. 

 When injected subcutaneously it produces various effects, such as 

 miction, defaecation, and abundant salivation, with accelerated 

 respiration followed by vomiting. The animal drinks with avidity, 

 and remains lying down, in a very depressed condition. Death 

 finally supervenes, from arrest of respiration and also of the heart's 

 action. The poison likewise acts upon the arterial tension, which 

 falls very rapidly and very markedly. The sensory nerves are also 

 attacked; irritability is at first increased, then diminished, and at 

 last entirely lost. These changes take place from behind forwards, 

 and from the periphery to the centre. The coagulability of the 

 blood is at first intensified and then lessened, as when acted upon 

 by ViPERiNE venom (H. Conpin).^ 



C. — Mammals. 



The only mammal that can be considered to be provided with 

 a poison-apparatus belongs to the Order Monotrcmata, and is known 

 as the Duck-billed Platypus {Ornithorhynchus paradoxus, or 0. 

 anatinus, fig. 125). The head of this animal is furnished with 

 a kind of flat duck's bill, armed with two horny teeth in the upper 

 jaw, while the body, which is covered with dense fur, resembles that 

 of a beaver. The tail is broad and flat ; the legs are short, and the 

 feet are provided with five toes, armed with strong claws and webbed. 



This singular animal is found only in Australia and Tasmania. 

 It lives in burrows near watercourses, entered by holes which it 

 digs in the bank, one above, the other on the water-level. It spends 



> H. Coupiii, La Nature, September 19, 1903. 



