RErTILE LIFE IN CAPTIVITY. 5 



their susceptibility to diseases and the infectious nature 

 of these conditions. The most dreaded affection is a 

 membranous condition of the mouth which spreads to 

 the fauces, and is known as " canker." This disease 

 gains entry to the mucous membrane inside the lips and 

 jaws through injury or abrasion. The animal becomes 

 ill-tempered and snappish, and ultimately dies, partly 

 as the result of starvation, through the inability of the 

 tissues to absorb food stuffs, and also partly from toxins 

 formed by the growth. 



Another snake disease is known as " casting disease," 

 and means that no sooner is the old slough cast than 

 another one begins, with the result that in a bad case the 

 unfortunate snake gets covered with a more or less thick 

 felted mass of partly shed scales. While snakes are 

 casting they will refuse food, and more especially when 

 in this chronic state. For canker I know of no actual 

 cure, but have always made a rule of isolating the 

 infected specimen and disinfecting the case thoroughly 

 to try and prevent the spread of this scourge. Casting 

 disease can at times be cured by bathing the animal in 

 water to which a little glycerine has been added. 



Snakes are carnivorous reptiles and require water 

 for drinking and bathing. They show considerable 

 diversity in their methods of taking their prey, the 

 poisonous species strike and usually wait the victim's 

 death. The constrictors kill their prey by encircling iis 

 body with their own folds, while others, as the grass 

 snakes — Tropidonotus — swallow frogs alive, catching 

 them by a leg. 



It is possible to get the pythons and boas to take 

 dead animals, but even then they will constrict them. 

 The capture and death of an animal by a constricting 

 snake is a remarkable process. Assuming that a rat is 



