Wee Is of Hairs. 8 3 



flexible elastic trichomes, set in a circle round the 

 inner surface of the tubular portion of the coroUa, 

 and having, each and all, their free ends turned towards 

 the centre of the tube. Such, for instance, is the 

 arrangement in Phlomis, Lamium, Leonurus, Stachys, 

 Ballota, and numerous other Labiatse, as also in many 

 SCrofularinese, especially in most species of Veronica, 

 and again in sundry Verbenaceee and AsperifoUse. The 

 position of this diaphragm of hairs within the tube is 

 variable ; sometimes it is placed near the mouth of 

 the tube, as in Verbena officinalis and AncJmsa arvensis 

 (Plate II. fig. 49), and as in Gentiana germanica and 

 G. nana (Plate II. fig. 72) ; sometimes it lies deeper 

 in towards the bottom of the tube, as for instance in 

 the Prunellas, in Horminium pyrenaimm (Plate III. 

 fig. 99, longitudinal section of flower ; fig. 100, transverse 

 section just in front of the diaphragm), and in Phlox 

 ;paniaiilata (Plate III. fig. 101, longitudinal section of 



basin-like hollows in which water collects, this water protects the 

 flowers from crawling animals, and is retained in the basins for a 

 considerable time ; but when flowers have this basin shape there 

 are numerous reasons why they should be prevented from getting 

 filled with water, and in fact they are so protected by manifold 

 contrivances (see A. Kerner ; Schutzmittel des Pollens gegeu die 

 Nachtheile vorzeitigen Dislocation und Befeuchtung). When there 

 is no special protective appliance, as for instance in those Saxifrageae 

 and TJmbelliferse whose flowers neither close nor bend downwards 

 nor sidewards during rain, it will be found that such protection 

 would be superfluous. The nectar in such flowers forms but a very 

 thin layer, and is neither weished away, nor even diluted by rain- 

 drops, for these, as also dew, run off the slimy layer of nectar, as if 

 from a varnished surface. 



