HARRIS AND KUCHS : OBSERVATIONS ON POLLINATION. 35 



18r buds, Vil buds, 2ir flowers, 21/ flowers. 



There seems to be no law governing the production of right- 

 and left-handed flowers on the opposite sides of the main axis 

 of the plant. Sometimes two right- or left-handed flowers will 

 be produced in succession on one side of the raceme, and some- 

 times right- and left-handed alternate on the same side. 



Concerning the method of pollination in ('. chamsecrista, the 

 writers have not been able to thoroughly satisfy themselves. 

 Todd says : " I consider the following explanation most prob- 

 able : In getting the pollen, some grains are dropped on the in- 

 curved petal, and by it made to adhere to points of the bee, 

 and to such points in a right-handed flower as will carry it to 

 the stigma of a left-handed flower, and vice versa." Robertson 1 ' 5 

 says : "The pollen, being thus forced out of the terminal anther 

 pores, falls either directly upon the bee or upon the lateral petal 

 which is pressed close against the bee's side. In this way the 

 side of the bee which is to the incurved petal receives the most 

 pollen. ... A bee visiting a left-hand flower receives 

 pollen upon the right side and then flying to a right-hand flower 

 strikes the same side against the stigma." 



It is very difficult to see just what takes place when the 

 flowers are visited by a large insect, but the writers have ob- 

 served that when they are visited by honey-bees, for instance, 

 the insect supports itself by hooking his left hind leg over the 

 terminal, upturned portion of the stigma in a right-handed 

 flower, and the right leg in a left-handed flower. The pistil 

 then would serve the function of support for the insect visitor. 

 It was noticed that sometimes bees would attempt to get the 

 pollen by approaching the flower from some direction other 

 than that described above. The insect usually failed in this, 

 and after one or two unsuccessful endeavors would give up the 



16. Robertson, Charles, lor. cit. 



