EFFECTS OF THE VENOM 



265 



3. Mucous discharges from the nose, respiratory organs, and 

 stomach. 



4. Very occasionally the mucous discharges are stained with 

 blood. 



Beyond obvious pain, the local effects are engorgement of the 

 vessels with blood, and effusion into the tissues. If the animal 

 recovers, there may be suppuration and sloughing of the affected 

 part. The effects on the nervous system seem to be due to the 

 action of the poison on the brain and spinal cord, and pari passu 

 on the motor nerve endings. The most evident paralysis is that 

 of the tongue, larynx, and pharynx, as evinced by the inability 

 to retain the saliva within the mouth, to move the tongue, or to 

 swallow. This is due to the action of the poison on the medulla. 



There is also, as indicated above, clear evidence of action upon 

 he respiratory centre, which has been carefully studied by Wall 

 and others, who show that in large doses there is a progressive slow- 

 ing, and in smaller doses first acceleration and then slowing of the 

 respirations. There appears to be but little effect upon the heart 

 and circulation or temperature. 



The effect on the blood in causing haemolysis was first demon- 

 strated by Cunningham, who considered it the main feature. Not 

 merely are the corpuscles dissolved, but the coagulability is re- 

 duced, and hence the blood-staining of the tissues and the urine 

 in experiments on' animals, provided that artificial respiration is 

 kept up. 



The effects of the venom on man are local pain in the neighbour- 

 hood of the bite, which appears as two small punctures about J inch 

 apart, usually exuding a blood-stained fluid. The pain increases in 

 severity, and spreads up the limb on to the body. In a short time 

 the victim feels intoxicated, and presently loses control of his legs, 

 which become paralyzed, as may other muscles, including those of 

 the jaw. There is often profuse salivation, and inability to speak 

 or swallow. The pulse and respirations increase for a time, and 

 then the breathing becomes slower, and death occurs from failure 

 of the respiration, while the heart continues to beat for a short 

 time after the respirations have ceased. 



If recovery takes place, the urgent symptoms abate, some slight 

 fever and local swelling occurs, while a large amount of urine is 

 passed. 



When examined post mortem, it will be found that the rigor 

 mortis is well marked, while the blood is fluid in man, but coagulated 

 in animals. If the corpuscles are examined soon after death, no 

 change will be noted, but later they alter, and blood-crystals, 

 indicating haemolysis, may form. The parotids may be swollen. 

 The brain is normal, but the pia mater is gorged with blood. The 

 muscles are often of a dirty red colour. The lungs in human beings 

 are generally congested, and the bronchi and smaller tubes filled 

 with thin frothy fluid^and intensely congested. Particles of food 

 or remedies are to be found in the air-tubes because of the paralysis 



