254 



HALF-HOURS IN THE GREEN LANES. 



eembles the pollen dust of the Broad-leaved Helle- 

 borine. The grains of a species of hawkweed usually 

 found growing near the sea (Hieracium subaudwn), 

 which plant has often puzzled the young botanist, 



Fig. 191. 



Pollen of Spear Thistle (Cnicus lanceolatus), Common Rush ( Junoui 

 conglomerates}, and Bitter Vetch (Orobus tuberosus\ 



Fig. 192. 



Pollen of Hieracium, su/jawdum, Erica cilians, and Green Mint 

 (Mattha tiridis}, 



perhaps, by the swellings on its stem, caused by an 

 insect, one of the cynips, having deposited its eggs 

 beneath the skin are surrounded by hairy cilia. 

 The pollen of one of our Lings (Erica ciliaris) is 

 triangular ; whilst that of the common green Mint 

 (Mentha viridis) is nucleated. 



The microscope, notwithstanding the discoveries 

 it has made in the investigation and determination 

 of vegetable tissues, has still much to do before we 



