FACULTIES OF INSECTS 133 



chrysalis. Perhaps there is no more remarkable instance 

 of this attribute of certain insects of arriving at, in a 

 manner incomprehensible to us, some object necessary for 

 the perpetuation of their species or advantageous to 

 their welfare, than the visits paid by a large bee to one of 

 our commonest orchids (Catasetum tridentatum) } This 

 bee, which Darwin describes as a Euglossa, is rarely seen 

 except when the Catasetum is in bloom. But then, it 

 does not matter where one of these plants may be, the 

 bees are sure to find it out. They appear as if by magic 

 in small swarms of five or six, or even ten individuals, as 

 soon as the buds expand, and they will continue their 

 visits, returning every morning to feast on the thick 

 viscid stuff distilled by the flowers during the night. In 

 their struggles to get at the nectar they are so passion- 

 ately fond of, they disturb the highly sensitive pollinia, 

 which fly out and attach themselves by a sticky disc 

 to the heads of their voracious guests. Should the bee 

 afterwards visit a female flower with his burden of pol- 

 linia he repays the hospitality he has enjoyed by assisting 

 in the propagation of the Catasetum, whose flowers will 

 at some future period furnish a delicacy for his descen- 

 dants, while ensuring the perpetuation of their species. 

 The female Kentish Glory, with her mysterious power of 

 attraction facilitating her impregnation ; the palm-beetle, 

 with its faculty of ascertaining when and where have 

 fallen the trees whose decaying pith furnishes food for its 

 larvae ; the perfect development of some particular sense 

 enabling the Euglossa bee to find out and indulge in the 

 luxury of which he is so fond ; the marvellous relation- 



' In his Fertilisation of Orchids Darwin has so fully described the 

 sexual forms of the flowers of this orchid that I think it needless to dilate 

 on the subject here, although it is an exceedingly interesting one. 



