100 



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 

 (Mercurialis) \ green. 



FIG. 34. Female flower of dog's 

 mercury {M ercurialis) \ 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 flowers to a naked ovary ; green. 



or involucres instead, as in the well-known latrophas 

 and Poinsettias of our hot-houses. This instance is 



