106 SCIENCE FROM AN EASY CHAIR 



As they slowly creep, in their growth, over the poisoned 

 animal, they absorb its life's blood painlessly and without 

 disturbing the death-slumber of the victim. Mr. Wells 

 supposes a retired civil-servant, with feeble health and a 

 passion for orchids, to have purchased an unknown speci- 

 men, which, after some months of nursing, is about to 

 blossom in the little hothouse of his suburban home. He 

 goes quietly and alone one afternoon, when his housekeeper 

 is preparing his tea, to enjoy the first sight and smell of 

 the unknown flower, and is found, some three hours later, 

 lying insensible before the orchid, which is giving out 

 an intoxicating odour, and is looking very vigorous and 

 wicked. A blood-red tint pervades its leaves and stalks, 

 and it has already pushed some of its finger-like shoots 

 round the orchid-lover's neck and beneath his shirt front. 

 When they are pulled away a few drops of blood flow 

 from the skin where the absorbent shoots had applied 

 themselves. The victim recovers. 



When we take a survey of the " stings " and poison- 

 fangs and spurs of animals, we find a much greater 

 abundance and variety of these weapons than in plants. 

 They serve animals not only as a means of defence, but 

 very often for the purpose of attacking and paralysing 

 their prey. We have to distinguish broadly between 

 (a) gut-poisons and (^) wound-poisons. The slimy sur- 

 face of the skin and the juices of animals are often 

 poisonous if introduced into wounds, but harmless if 

 swallowed, though in the toad and salamander the skin 

 contains a poison which acts on the mouth and stomach. 

 Thus the blood of the eel is poisonous to higher animals 

 if injected beneath the skin, though not poisonous when 

 swallowed. Pasteur found that the saliva of a healthy 

 human baby a few weeks old produced convulsions when 

 injected beneath the skin of a rabbit. The fluid of the 

 mouth in fishes (Murcena), in some lizards (Helodermd], 



