9a 



VANILLA. 



In the ariicle on Vanilla, in last issue of the Balletin, reference is 

 made to a drawing of the flower and its parts in Bulletin for Oct. 1888. 

 That drawing is now reproduced for the benefit of those who may not 

 possess a copy of the earlier Bulletin. 



Explanation of Platk. 



Fig. 1. — PortioD of stem ot Vanilla plant, with leaf, serial root, and 

 cluster of flowers ; a, front view of Vanilla flower ; 6, side 

 view ; c aerial root, with root hairs. 



Fig. 2.- — Single flower of Vanilla, exhibiting the first stage in the pro- 

 cess of artificial fertilisation. The operator, provided with a 

 finely-pointed piece of bamboo, divides the lip or labellum 

 medially, so that the central lobe is separated from the two 

 side lobes. This exposes the column and organs of fecunda- 

 tion. The instrument is represented as placed against the 

 column, ready to press upwards the anther a, and bring the 

 pollinia in contact with the stigma h. 



Fig. 3. — Single flower of Vanilla, exhibiting the second stage in the 

 process of artificial fertilisation ; h shows position of column 

 exposed by division of the lip [the middle lobe of lip is pulled 

 forward and curled upon itself to show the position of the 

 column ; the side lobes of lip, separated as shown in Fig, 2, are 

 represente'^ at back of the column] ; a, the position of pollen 

 masses, taken from the anther and placed on the stigma. 



Fig. 4. — Enlarged front view of top of the column ; a, the anther. 



Fig. 5. — Enlarged side view of top of the column ; a, the anther ; 6, the 

 stigma, or viscid surface on which the pollen masses must be 

 placed to ensure fertilisation. 



Fig. 6. — Enlarged section through top of the column ; a, one of the 

 pollen masses in situ ; 6, the stigmatic cavity. 



Fig. 7. — Enlarged section through top of the column ; a, the pollen 

 masses, havinii^ been transferred from a, Fig. 6, are now re- 

 presented in contact with the stigmatic surface. [Although 

 diagraramatically shown, these figures give a tolerably good 

 idea of what is actually necessary in order to produce fertili- 

 sation in a Vanilla flower. | 



