CHAP. III. PULMONARIA OFFICINALIS. 101 



of nectar secreted. Lastly, L. Lewisii is said by Plan- 

 chon 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.* 



PULMONARIA ( 



Pulmonaria ofjlcinalis. Hildebrand has published f 

 a full account of this heterostyled plant. The pistil 

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

 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. 

 70 per cent.) had set fruit, yielding 1.86 seed per 

 fruit. So that the short-styled plants produced many 

 more flowers, and these set a rather larger proportion 



* Planchon, 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,' 1865, Jan. 13, 



Asa Gray, in ' American Journal p. 13. 



