c ross — Eupatorium ageratoides and coelestinum. J65 



in diameter than the area bearing the sweeping hairs enters 

 the otherwise empty cylinder, the pressure is reduced 

 and a probable transfer of liquid diminishes the tumes- 

 cence of the filaments which bend themselves at point 



rt, Fig. 4, and draw down the cylinder from over the 

 stigmatic area. In E. coelestinum (Pig. 6) the stigmatic 

 branches are further carried up by the unfolding of the 

 loop-like curvature in the style. The pollen thus carried 

 out of the anther cylinder falls upon the corolla, and is at 

 once carried away by insects, or by the wind ; this closes 

 the first or staminate stage. The stigmatic surfaces readily 

 develop their papillae and secrete stigmatic fluid. When 

 by frequent observations the pistillate stage was determined 

 in the first lot of plants selected, two of the first four plants 

 were carefully cross-pollinated by hand, and two were close 

 pollinated in the same manner. The second four plants 

 were left undisturbed until put in press, as were also those 

 exposed. In the second lot selected, two of the first four 

 plants were cross-pollinated, and two were close pollinated. 

 The second four, in which half the inflorescence was pro- 

 tected, and half exposed, were left undisturbed until put in 

 press, when ninety-five per cent, of the fruits grown on 

 exposed parts were well developed, while sixty-two per 

 cent, of fruits grown on protected parts were apparently 

 good — showing an increase of over fifty per cent, in favor 

 of exposed plants. The plants with separate branches pro- 

 tected were also cross and close pollinated ; while the last 

 two of the second choice were left exposed, to compare with 

 the last four of the first choice. Ninety-four per cent, of 

 the fruits were matured in each case. 



The immature condition of the stigma at the time the 

 pollen is swept out of the anther cylinder clearly indicates 

 cross-pollination, whatever the agency may be. The pollen 

 is carried from the corolla by nectar or pollen-feeding 

 insects, or by the wind. If removed by insects, as seems 

 most probable, they carry it from flowers in the staminate 

 stage, to those in the pistillate as they pass over the capitu- 



