154 ENTOMOLOGICAL NEWS. [April, '08 



across the projecting point of the stigma. In flava especially, 

 egress is exceedingly difficult except at the five entrance holes ; 

 and all of the numerous insects observed visiting these flow- 

 ers emerged after considerable struggling through one of 

 these orifices, almost invariably again scraping the stigma in 

 their departure. In flava therefore, with its heavy closely- 

 overlapped petals usually preventing the escape of the visit- 

 ing insects except by repassing the stigma, some special pro- 

 vision for preventing habitual self-pollination by insect ag- 

 ency would be expected ; and this seems to be provided for in 

 the position the flower assumes upon its stem at various ages. 

 When the bud first appears above the ground it is borne up- 

 right upon the stem ; as the blooming period draws near, the 

 stem bends just below the bud, making a complete turn, so 



that when the flower opens the style occupies the position 

 of an inverted umbrella, catching and retaining the falling 



pollen, most of which is shed within twenty-four hours after 

 the flower begins to open. The flower then begins again to 

 change its position, often being very noticeably tilted on the 

 stem by the third day, and eventually, long before the fall of 

 the petals, it takes a position at right angles to the original 

 one. These changes of position and the structure of the flower 

 are shown on Plate IX. The tilted and finally upright flow- 

 ers naturally retain less pollen than the newly opened horizon- 

 tal ones, and often the tilted flowers show little trace remain- 

 ing of the abundant supply in the newly-opened blooms. As^ 

 the blossoms remain fresh and continue to be attractive to 

 insects for more than two weeks, it would seem that this 

 change in the position of the flower and the consequent spill- 

 ing of the pollen decidedly favor cross-fertilization. 



Ants are almost invariably present in the flowers, attracted 

 by the abundant nectar oozing from the ovary, but they arc 

 probably of little importance as pollenizers. The ant most 

 abundant in flava at Summerville is identified by Prof. W. M. 

 Wheeler as Tapinoma pruinosa Roger. Ants, wasps, and oc- 

 casionally butterflies visit the outside of the flower; spiders, 



