SERPENTS. 



149 



The tube thus formed communicates with the 

 poison-bag, into which the deadly fluid is poured 

 from glands which lie on each side of the head 

 beneath the eye. Each consists of a number of 

 long narrow lobes, extending from the main 

 duct which runs along the lower border of the 

 gland upwards and slightly backwards. Each 

 lobe gives off smaller lobes from its sides, and 

 each of these is subdivided into smaller secreting 

 sacs ; and the whole gland is surrounded by a 

 membrane connected with the muscles, by whose 



POISON-GLAND. 



contraction the several lobes are -pressed and 

 emptied of the poison. This fluid is then con- 

 veyed through the duct to the poison-bag. "AVe 

 may suppose," says Professor Muller, " that as 

 the analogous lachrymal and salivary glands in 

 other animals are most active during particular 

 emotions, so the rage wdiich stimulates the venom- 

 snake to use its deadly weapon must be accom- 

 panied with an increased secretion and great 

 distention of the poison-glands ; and as the action 

 of the compressing muscles is contemporaneous 



