57 



are curved in order to bring all the anthers close together 

 around the styles. The green petals are few in number, 

 much shorter than the stamens, of a tubular form with 

 erose edges, and half filled with nectar. This arrangement 

 has evident relation to cross-pollination. To reach the 

 nectar an insect must alight on the sepals and thrust its 

 head into the flower ; but cannot well do so without bringing 

 its body into contact with the stigmas. After these have 

 been fertilised by pollen brought from an older flower, they 

 are hidden among the anthers owing to the extension of the 

 filaments. Then the sepals part more widely, the anthers 

 separate somewhat and discharge their pollen. Insects pro- 

 bably settle upon them, and so dust their undersides with 

 pollen. At this stage the outer sepals develop a thin line of 

 crimson along their upper edges ; after the emptying of the 

 anther-cells this line becomes thicker and more purple, but 

 remains distinctly on the red side of purple. 



" The fact that the stations mentioned are on enclosed 

 land precludes one from making observations that one feels 

 to be necessary in order to establish satisfactorily the means 

 by which this plant is fertilised. The purple line is not 

 developed as an attraction to insects, and cannot be intended 

 as an indication to them that, fertilisation having been 

 effected, it is useless to call, for there may still be a consider- 

 able quantity of nectar in the petals after all the pollen has 

 disappeared and the purple line is well developed. 



" So far as the records go, it appears to be fertilised 

 chiefly by Apis and Bombus, but it is also visited by Eristalis 

 for the sake of its pollen. 



"If one were guided solely by coloured illustrations and 

 text-book descriptions, one might suppose that the purple 

 line in conjunction with the foetid odour of the flowers indi- 

 cated an attraction for flies ; but though the odour may serve 

 this purpose, the colour not being developed until after 

 pollination somewhat weakens the supposition. Possibly, 

 the purple line may be developed to attract Diptera as a 

 last resource. (It may be noted that the text-books are con- 

 tented with stating that the sepals have a purple border, but 

 do not mention that this is developed after the flowers open.) 

 Lord Avebury supposes that the odour is for the purpose of 

 repelling browsing animals ; but for this to be true the 

 unpleasantness should be in the leaves which are present all 

 the year. So far as I can make out, no offensive odour is 

 given off by the foliage. Hooker says, ' Plant foetid and 

 cathartic' The cathartic properties would be a sufficient 



