Chap. III. PULMONAEIA OFFICINALIS. 101 



may be suspected that they are frequented during 

 the night by small moths for the sake of the five 

 minute drops of nectar secreted. "Lastly, L. Lewisii 

 is said by Planchon to bear on the same plant flowers 

 with stamens and pistils of the same height, and 

 others with the pistils either longer or shorter than 

 the stamens. This case formerly appeared to me an 

 extraordinary one ; but I am now inclined to believe 

 that it is one merely of great variability.* 



PULMONAEIA (BOEAGINEiE). 



Pulmonaria officinalis. — Hildebrand has published t 

 a full account of this heterostyled plant. The pistil 

 of the long-styled form is twice as long as that of tho 

 short-styled ; and the stamens differ in a corresponding, 

 though converse, manner. There is no marked dif- 

 ference in the shape or state of surface of the stigma 

 in the two forms. The pollen-grains of the short- 

 styled form are to those of the long-styled as 9 to 7, 

 or as 100 to 78, in length, and as 7 to 6 in breadth. 

 They do not differ in the appearance of their contents. 

 The corolla of the one form differs in shape from that 

 of the other in nearly the same manner as in Primula ; 

 but besides this difference the flowers of the short- 

 styled are generally the larger of the two. Hilde- 

 brand collected on the Siebengebirge, ten wild long- 

 styled and ten short-styled plants. The former bore 

 289 flowers, of which 186 (i.e. 64 per cent.) had set 

 fruit, yielding 1'88 seed per fruit. The ten short- 

 styled plants bore 373 flowers, of which 262 (i.e. 



* PlanehoTi, in Hooker's ' Lon- of Science,' vol. xxxvi. Sept. 1863, 



don Journal of Botany,' 1848, vol. p. 284. 



vii. p. 175. See on "this subject t ' Bot. Zeitung,' 1SG5, Jun. 13, 



Asa Gray, in ' Ameiican Journal p. 13. 



