III.] ORCHJDACEAL, 3^9 



In Vanda the two polliiiia are connected to a single 

 " pedicel " (as Mr. Darwin calls it), which pedicel is attached 

 to a viscid disk at its lower end. 



In Dendrohiw7i the small two-celled anther is terminal, 

 the anther-case forming a minute cap at the top of the 

 column. It encloses four pollinia, connected in pairs, one 

 pair in each cell of the anther. They are not provided 

 with either a caudicle or viscid disk. 



Fig. 203. Pollinia, caudicle, and Fig. 204. Longitudinal section of column of 

 gland of Vanda. Dendrobiuin. To the left the pollen detached. 



From observations which have been recently published 

 by Mr. Charles Darwin,* it is shown that the peculiar modi- 

 fications of the pollen characteristic of Orchids stand in 

 relation to the part fulfilled by insects in securing their 

 fertilisation. As his observations have not been generally 

 extended to Indian species, I shall briefly describe the 

 structure and mode of fertilisation in a common British 

 Orchis, presenting, in the structure and relative position of 



* " On the Fertilisation of Orchids." Murray. 



