Drop-bar Arrangement. 1 2 1 



t 



A very peculiar arrangement, which must here be 

 noticed, is found in the flowers of Chelone and Penta- 

 stemon, and may not inappropriately be called the 

 "drop-bar arrangement."^ The Pentastemon genfian- 

 oides, so widely diffused as an ornamental plant, will 

 serve as an example. (Plate I. fig. 34, longitudiaal 

 section ; fig. 35, transverse section near base of flower.) 

 The nectar in this flower is very abundant, and is secreted 

 by the basal parts of the two shorter stamens, which 

 are inserted on the corolla to the right and left re- 

 spectively of the ovary. The nectar is secreted on the 

 outer side of the stamens, that is on the side turned 

 from the ovary and towards the corolla, and com- 

 pletely fills up the pouch-like spaces which lie between 

 the latter and the secreting surfaces. It is impos- 

 sible for the nectar to trickle out from these lateral 

 spaces in a downward direction, because the dilated 

 stamens are in close apposition with the inner surface 

 of the corolla by their lower edges. But, on the other 

 hand, there is a free communication between the two 

 lateral pouches and the space above the ovary; and, 

 as a matter of fact, this upper space, which is 3 mm. 

 in width, and over-arched by the corolla, is invari- 



^ [I know of no English equivalent for the German Schjagbaum, 

 and have therefore invented the term drop-har. By it is meant 

 an arrangement in common use in Germany as a harrier or toU-har ; 

 consisting of a horizontal bar attached by one end to an upright, 

 and moveable on that end up and down in a vertical direction. — 

 Editor.] 



K 



