Cavity closed by Stamens. 105 



In front of this nectar-pit is a scale-like excrescence, 

 which is given off from the lamina at an angle of from 

 40 to 50 degrees. The stamens, which radiate in great 

 number from the centre of the flower, and form several 

 closely superposed whorls, lie immediately above these 

 scales, the filaments being in direct contact with their 

 margins. Thus a small closed nectar-cavity is formed 

 at the base of each petal ; and this is only accessible to 

 such insects as are strong enough either to lift up the 

 obstructing filaments or to push down the scale. 



In this species, then, instead of a single nectar- 

 cavity, there are as many cavities as there are petals. 

 In many other Eanunculacese, e.g., in some large- 

 flowered species of Clematis and Atragene, the number 

 of closed nectar-cavities is still greater ; and there are 

 actually almost as many of them as there are stamens. In 

 Atragene alfina, L., for example (Plate I. fig. 14, longi- 

 tudinal section of flower, natural size ; fig. 1 5, a single 

 anther — twice natural size ; fig. 16, a group of anthers, 

 placed one behind the other, and covering each other — 

 twice size of nature), the filaments are somewhat 

 dilated in their lower half ; and each petaloid dilata- 

 tion is hollowed out on the side turned towards the 

 gynsecium into a groove in which nectar is secreted. 

 Now there are numerous whorls of stamens ; and as 

 the hinder whorls successively cover in those in front 

 of them, and are closely applied to their posterior sur- 

 faces, and as, moreover, the whole mass of stamens is 



I 



