POISONOUS PLANTS AND ANIMALS 105 



well known that only certain individuals are liable to the 

 more violent and serious form of hay fever. It is not at 

 all improbable that this irritation of the air passages, 

 often attributed to the mechanical action of the pollen of 

 grass and other plants really is due to minute quantities 

 of a poison like that of the poison-vine, present in the 

 pollen of some hay plant yet to be suspected, tried, and 

 convicted. 1 



With regard to a poisonous action at a distance being 

 possibly exerted by plants, we must not overlook the 

 effects of some perfumes discharged into the air by 

 flowers. Primarily such perfumes appear to serve the 

 flowers by attracting to them special insects, by whose 

 movements and search for honey in the flowers the pollen 

 of one is conveyed to another and fertilisation effected. 

 Human beings are sometimes injuriously affected by the 

 heavy perfume given out by lilies and other flowers, 

 headache and even fainting being the result. No instance 

 is known of serious injury or death resulting in the 

 regions where they grow from the overpowering perfume 

 of such flowers. But that admirable story-teller, Mr. H. 

 G. Wells, has made a legitimate use of scientific possibilities 

 in imagining the existence of a rare tropical orchid which 

 attracts large animals to it by its wonderful odour. The 

 effects of the perfume are narcotising ; the animal, having 

 sniffed at the orchid, drops insensible at the foot of the 

 tree trunk on which the orchid grows. Then the orchid 

 rapidly, with animal-like celerity, sends forth those smooth 

 green fingers or " suckers," which you may see clinging 

 to the pots and shelves on which an orchid is growing 



1 Since the above was written, I have seen the account by an 

 American physician in a recently issued volume of Osier's Treatise 

 on Medicine of his recent discovery of the grass which produces in 

 its pollen the poison of hay fever, and of the preparation by him of 

 an anti-toxin which appears to give relief to those who suffer from hay 

 fever. 



