Chap. II. BONATEA SPECIOSA. 77 



together. As in Platanthera jlava, there is a process 

 at the base of the labellum which compels moths to 

 enter the flower on either side. The nectary, accord- 

 ing to Mr. Trimen and Mr. J. Mansel Weale, does not 

 contain free nectar ; but the hitter author believes 

 that the tissue of which it is composed tastes sweet, so 

 that moths probably penetrate it for the sake of the 

 intercellular fluid. The pollinia are of astonishing 

 length, and when removed from their cases hang down 

 merely from the weight of the j)ollen-masses, and if 

 attached to the head of an insect would be in a proper 

 jjosition for adhering to the stigma. Mr. Weale has 

 likewise described some other South African species 

 of Bonatea.* These differ from B. speciosa in having 

 their nectaries full of nectar. He found a small 

 butterfly, Pijrgus elnio, " perfectly embarrassed by the 

 number of pollinia of this Bonatea attached to its 

 sternum." But he does not specify whether the 

 sternum was naked or covered with scales. 



The South African genera Disa and Disperis are 

 placed by Lindley in two sub-tribes of the Ophreas. 

 The superb flowers of Disa grcmdijiora have been 

 described and figured by Mr. Trimen.f The posterior 

 sepal, instead of the labellum, is developed into a large 

 nectary. In order that insects may reach the copiously 

 stored nectar, they must insert their proboscides on 

 either side of the column; and in accordance with 

 this fact the viscid discs are turned outwards in an 

 extraordinary manner. The pollinia are crooked, and 

 when removed bend downwards from their own weight, 

 so that no movement is necessary for placing themselves 

 in a proper position. Considering the large supply oi 



* ' Journ. Linn. Soc. Bot.' vol. T ' Journ. Liun. Sue. Cot. voi 



X. p. 470. vii. 1SG3. p. lU. 



