146 EriDENDREiE. Chap. V 



Those species which I have examined of Laelia, 

 Leptotcs, Sophronitis, Barkeria, Phaius, Evelyna, 

 Bletia, Chysis, and Coelogyne, resemble Cattleya in 

 the caudicles of the pollinia being free, and in the 

 viscid matter from the rostellum not coming into 

 contact with them without mechanical aid, as well as 

 in their general manner of fertilisation. In Coelogyne 

 crisfata the upper lip of the rostellum is much elon- 

 gated. In Evehjna carivata and Chysis eight balls of 

 waxy pollen are all united to a single caudicle. In 

 Barkeria the labellum, instead of enfolding the column, 

 is pressed against it, and this would effectually compel 

 insects to brush against the rostellum. In Epidendrum 

 we have a slight difference ; for the uj)per surface of 

 the rostellum, instead of permanently remaining mem- 

 branous, as in the above-named genera, is so tender 

 that by a touch it breaks up, together with the whole 

 lower surface, into a mass of viscid matter. In tliis 

 case the whole of the rostellum, together with the 

 adherent pollinia, must be removed by insects as they 

 retreat from the flower. I observed in E. glaucum that 

 viscid matter exuded from the upper surface of the 

 rostellum when touched, as happens with Epipactis. 

 In fact it is difficult to say, in these cases, whether 

 the upper surface of the rostellum should be called 

 membrane or viscid matter. With Chysis this matter 

 sets nearly hard and dry in twenty minutes, and 

 quite so in thirty minutes after its removal from the 

 rostellum. 



In Epidendrum floribundum there is a rather greater 

 difference : the anterior horns of the clinandrum (i. e. 

 the cup on the summit of the column in which the 

 pollinia lie) approach each other so closely as to 

 adhere to the two sides of the rostellum, which con- 

 sequently lies in a nick, with the pollinia seated over 



