THE FRUITING OF THE BLUE FLAG 
(IRIS VERSICOLOR L.). 
JAMES G. NEEDHAM. 
AT the time of the adjournment of my college classes last 
June, I spent a few hours afield, watching the blue flags and 
their insect visitors, at first solely for the pleasant recreation 
that such study affords. But I soon made a few enticing 
little discoveries which set me to work in earnest. I began by 
locating all the clumps that were easy of access from my 
home in Lake Forest, and then I studied them daily during 
the flowering season, and almost daily thereafter throughout 
the summer. 
The facts that first caught my attention were: (1) that there 
are many visitors to these flowers that seem to have been 
unnoticed hitherto; (2) that most of these are illicit visitors ; 
and (3) that the ill-adapted ones are habitually deceived by the 
flower itself as to its proper entrance. I propose to give in the 
following pages the more important results of the season's 
observations. 
It seemed to me that any new study of this so familiar 
flower should be undertaken on somewhat broader lines than 
are usually followed. The reproductive phase of the plant is a 
unit, and the flower is but one of a series of devices for fur- 
thering the reproductive process. Bud and flower and capsule 
and seed are the successive centers of interdependent ecologi- 
cal phenomena, determining the start in life of the next gener- 
ation. I have tried to study the effect of insects upon the 
outcome of the reproductive process as a whole, and I discuss, 
below the chief ecological relations under the following head- 
ings: Pollination ; The Waste of the Nectar; The Destruction 
of the Flowers; Fertilization ; The Destruction of the Seeds; 
Inflorescence, and Chances of Maturing Fruit; The Relation 
of Habitat to Fertility; Alteration of Environment. 
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