VII.] CATASETUM. 181 



of this genus is immersed in a viscid fluid, by means 

 of which it adheres firstly to the insect, and secondly 

 to the stigma, while in most Orchids it is the stigma 

 which is viscid. In a Trinidad species, Coryanthes 

 macrantha, according to Dr. Cruger, the basal part 

 of the lip forms a bucket, which secretes a copious 

 fluid which wets the wings of the bees, and by 

 rendering them temporarily incapable of flight, com- 

 pels them to creep out through the small pas- 

 sages close to the anther and stigma ; thus securing, 

 though by different means, the object which in Cypri- 

 pedium is effected by the inflected margins of the 

 labellum. (Jour. Linn. Soc., 1864.) 



Such are a few of the remarkable contrivances ex- 

 isting among British Orchids. I must refer those who 

 wish for more detailed information to Mr. Darwin's 

 charming work. 



Although I have thought it well to confine myself 

 for the most part to illustrations taken from our 

 common wild flowers, I cannot resist mentioning 

 the case of Catasetum, one of the Vandeae, which as 

 Mr. Darwin says, are "the most remarkable of all 

 Orchids." In Catasetum, the pollinia and the stig- 

 matic surfaces are in different flowers, hence it is 

 certain that the former must be carried to the latter 

 by the agency of insects. The pollinia moreover are 

 furnished with a viscid disk, as in Orchis, but the 

 insect has no inducement to approach, and in fact 

 does not touch, the viscid disk. The flower, however, 

 is endowed with a peculiar sensitiveness, and actually 

 throws the pollinium at the insect. Mr. Darwin has 

 been so good as to irritate one of these flowers in my 



