POGONIA 67 



lip, which, the moment an insect lights on it, shuts up like 

 a spring against the anthers, carrying the insect into a 

 little prison formed of the petals and a sepal, that arch in a 

 hood over the column. This stays closed for about half 

 an hour, before it opens to set him free, so that whether or not 

 he finds nectar to beguile his stay, he cannot escape until he 

 has become well smeared with pollen to take to the next 

 flower. 



The aromatic pod from which vanilla is derived is the 

 fruit of an orchid belonging to this group. It is a native 

 of South America, but is transplanted by growers to foreign 

 countries, where it blooms profusely, secretes plenty of nectar, 

 but never sets the valuable pods, unless the planters deliber- 

 ately transfer the pollen from one plant to another Either 

 the insects are not adapted in size, or length of tongue, or 

 they do not crawl in and out in just the right way to carry 

 oflF the pollen, or else they do not care to try the foreign 

 nectar. Possibly the nectar may have the same effect on the 

 unaccustomed insect that was observed when a British bee 

 was formally invited to enter a hothouse orchid from 

 Guatemala that closely resembled the vanilla orchid. He 

 pushed his way in, sipped the nectar, backed out and 

 keeled over on the labellum, where he lay with legs stretched 

 out, as if dead. By-and-by he recovered, but doubtless 

 with sufficient experience to warn him against any further 

 attempt at satisfying his hunger with such intoxicating 

 cordial, and incidentally cross fertilising that particular 

 species of foreign orchid. 



