lOO 



THE COLOURS OF FLOWERS. 



too, that when these degenerate, but still entomophilous, 

 green flowers have found it desirable to attract insects 



Fig. 33. — Male flower of dog's mercury 

 (Merctirialis) ; green. 



Fig. 34. — Female flower ot dog's 

 mercury {Mercurt'alis)', green. 



by developing new coloured surfaces in place of the 

 lost corolla, they have not done so by producing a 

 fresh set of petals, but have acquired coloured bracts 



Fig. 35.— Inflorescence of spurge {Euphorbia), the male flowers reduced to a single 

 stalked stamen, the female fljwers to a naked ovary ; green. 



or involucres instead, as in the well-known latrophas 

 and Poinsettias of our hot-houses. This instance is 



