CHAP. III. LINUM PERENNE. 95 



have expanded, the five stigmas twist round so as to 

 face the circumference, owing to the torsion of that 

 part of the style which lies beneath the stigma. I 

 should state that the five stigmas do not always turn 

 round completely, two or three sometimes facing 

 only obliquely outwards. My observations were made 

 during October; and it is not improbable that earlier 

 in the season the torsion would have been more com- 

 plete; for after two or three cold and wet days the 

 movement was very imperfectly performed. The 

 flowers should be examined shortly after their ex- 

 pansion, as their duration is brief; as soon as they 

 begin to wither, the styles become spirally twisted all 

 together, the original position of the parts being thus 

 lost. 



He who will compare the structure of the whole 

 flower in both forms of L. perenne and grandiflorum, 

 and, as I may add of L. flavum, will not doubt about 

 the meaning of this torsion of the styles in the one 

 form alone of L. perenne, as well as the meaning of 

 the divergence of the stigmas in the short-styled 

 form of all three species. It is absolutely necessary, 

 as we know, that insects should carry pollen from 

 the flowers of the one form reciprocally to those of 

 the other. Insects are attracted by five drops of 

 nectar, secreted exteriorly at the base of the stamens, 

 so that to reach these drops they must insert their 

 proboscides outside the ring of broad filaments, be- 

 tween them and the petals. In the short-styled form 

 of the above three species, the stigmas face the axis of 

 the flower; and had the styles retained their original 

 upright and central position, not only would the stig- 

 mas have presented their backs to the insects which 

 sucked the flowers, but their front and fertile surfaces 

 would have been separated from the entering insects 



