POISON APPARATUS 65 



of a great length, extending along each side of the 

 body and terminating in front of the heart. Instead 

 of the muscles of the temporal region serving to 

 press out the poison into the duct, this action is 

 performed by those of the side of the body. 



When biting, a Viperid snake merely strikes, dis- 

 charging the venom the moment the fangs penetrate 

 the skin, and then immediately leaves go. A Pro- 

 teroglyph or Opisthoglyph, on the contrary, closes 

 its jaws like a dog on the part bitten, often holding 

 on firmly for a considerable time. 



The poison, which is mostly a clear limpid fluid of 

 a pale straw or amber colour, more rarely greenish, 

 sometimes with a certain amount of suspended 

 matter, is exhausted after several bites, and the 

 glands have to recuperate. 



It must be added that the poison can be ejected 

 otherwise than by a bite, as in the so-called Spitting 

 Snakes of the genera Naia and Sepedon. The fact 

 that some of these deadly snakes when irritated are 

 in the habit of shooting poison from the mouth, at a 

 distance of 4 to 8 feet, even apparently aiming 

 at a man's face, has been too often witnessed in 

 India and Malaya, and especially in Africa, from the 

 days of the ancient Egyptians, for any doubt to 

 subsist as to their being endowed with this faculty, 

 but the mechanism by which this action is produced 

 has not been satisfactorily explained. In all proba- 

 bility, the poison escapes from the sheath of 

 5 



