LUTNEAlf SOCIETT OF LONDON. 8 1 



noteworthy also that whilst the wood violet relies upon its strong 

 perfume for drawing the few insects which fly in the spring to its 

 flowers, not attempting to raise its flowers above the vegetation 

 surrounding it ; the dog violet raises its flowers and makes itself 

 conspicuous by their light violet colour, dispensing with perfume 

 altogether. 



The wood sorrel {Oxalis Acetosella), like the wood violet, flowers 

 in very early spring, and forms colonies of bright green small 

 plants by means of underground stems in shady situations in 

 woods. It selects situations where at this early period of the 

 year vegetation is not abundant, and when the contrast between 

 these colonies of bright green plants serves to attract the few 

 insects on wing from some distance ; its delicately-tinted corolla 

 serving as a sign to insect visitors that nectar may be found 

 within. This has likewise small, inconspicuous cleistogamous 

 flowers, which carefully bury the capsule in the ground ; the 

 mature capsules being surprisingly large. These serve to re- 

 invigorate the colonies, but the perfect flowers of these plants 

 raise their capsules high up in the air, and are pi'ovided with 

 mechanism serving to shoot the seeds to a great distance, a feat 

 which later in the season \a ould be impossible — the seeds would 

 then be obstructed by other plants. 



It is noteworthy that in the above plants both tho stolons and 

 the cleistogamous flowers co-operate with the other organs in the 

 very important function of enabling the species to contend against 

 the competition in the environment in which it lives. The manner 

 in which the cleistogamous flowers supplement the action of the 

 creeping stems in producing dense colonies is peculiarly instruc- 

 tive. The important function served by these organs appears to 

 have been overlooked by botanists. 



It appears to me doubtful whether, the bisexual process of 

 reproduction having been perfected, the less perfect method by 

 offshoots, or degenerate cleistogamous flowers, would survive, 

 unless they showed some important secondary functions beyond 

 the reproduction of the species. 



LINJf. SOC. PBOCEEDINGS. — SESSION 1906-1907. 



