370 THE SNAKES OF SOUTH AFRICA. 



venom upon the walls of the blood vessels allows the blood to 

 ooze through and into the tissues, causing purplish blue patches 

 under the skin. The escape of blood through the walls of the 

 capillaries is always greatest near the small arteries owing to 

 the increased blood pressure at these places. The effect of 

 Viperine venom upon the circulatory system seems to be three- 

 fold — the red corpuscles are in most cases acted upon, causing 

 them to release their haemoglobin or colouring matter, and to 

 distort and alter their natural shape ; the phagosytes or white 

 blood corpuscles are more or less broken up ; the cells composing 

 the walls of the smaller blood vessels are caused to expand, 

 allowing the blood to escape into the surrounding tissues. 



Effects of Viperine Venom. 



In Viperine poisoning, such as is occasioned by the bite of the 

 Puff Adder, there is always grave danger of death supervening 

 from gangrene or extensive suppuration, owing to the haemorrhage 

 into the tissues in various parts of the body. Death may occur 

 from these causes a week or more after the infliction of the bite. 

 The haemorrhage or extravasation of blood into the tissues occurs 

 more or less extensively in patches, causing bluish-black dis- 

 colouration. There is also oozing of blood from the mucous 

 surfaces of the mouth, lungs, bowels, kidneys, bladder and 

 stomach ; and sometimes suffusion of blood into the brain 

 tissues. If this latter should take place death follows at once. 



I have many times examined natives with large cavities in 

 the calves of their legs, due to the sloughing away of the flesh 

 around the site of the bite of a Puff Adder. Other cases have 

 come under my observation where the flesh sloughed to a certain 

 extent around the part bitten, then healed, only to break out 

 again later and discharge a quantity of matter, and remain in a 

 suppurating condition for a month or two, and finally heal. This 

 suppuration and subsequent healing of the wound occurred at 

 intervals, in one case extending over a period of three years. In 

 this latter case most of the calf of the man's leg had sloughed 

 away. Yet he eventually recovered. Now and then men and 

 domestic animals after recovery from Adder venom poisoning 

 permanently lose their senses of sight, hearing, and smell. This 

 has never been known to occur when anti-venomous serum has 

 been freely used. 



