22 



spines, emerging each from a depression^at the side of and 

 behind the anus. No canal passes through these, the 

 spermatic ducts terminating some distance within the cloaca. 



Nearly all these organs are liable to be infested with 

 entozoa. The mouth, lungs, and digestive canal bear little 

 red round worms of several kinds ; but Tropidonotus quin- 

 cunciatus is remarkable for having its cellular tissue and 

 abdominal cavity inhabited by numbers of small tape-worms 

 about 6 inches in length. I believe that they are developed 

 from cysts in frogs and fishes. Both kinds of entozoa per- 

 meate the muscular tissues ; I have found them emerging 

 from under the skin of the tail, both in the abovementioned 

 snake and in a tree-snake.* 



Perhaps this Chapter will be the most fitting place for a 

 short notice of the monstrosities met with in this order of 

 vertebrates. By far the commonest monstrosity is the 

 possession of a double head, each head being perfectly 

 formed and the two placed side by side. These double- 

 headed snakes are by no means uncommon ; they have been 

 met with in America, Australia and Europe, they do not, 

 however, appear to survive their birth long, the specimens to 

 be found in museums being of small size. 



There is a young two-headed Tropidonotus quincunciatus 

 in the Madras Museum, its origin is unknown, as I found it 

 amongst a large number of snakes accumulated in the store- 

 rooms of the Museum. This monstrosity is, apparently, 

 rather common amongst the sea-snakes. It is possible that 

 a double-headed snake originated the fable of Ananden 

 the thousand-headed naga, and his humbler representative 

 the Sesha or seven-headed naga so often represented in 

 Hindoo religious art. 



• Snakes are externally troubled with the dog-tick. This parasite 

 gets between the scales and fastens on to the skin. 



