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Cornell Extension Bulletin io 



is then receptive to pollen. The flowers are usually protandrous, which 

 means that the stamens and pistil mature at slightly different times. It 

 is interesting to note that in Gladiolus segetum the pistil curls down to 

 receive the pollen, the stamens and pistils being ripe simultaneously. 



The first operation in 

 crossing is to protect the 

 pistil from foreign pollen 

 or pollen not wanted as a 

 parent of the cross. This 

 is done by taking out the 

 stamens or removing the 

 whole corolla to which the 

 stamens are attached. This 

 process is known as emas- 

 culation. Unless the sta- 

 mens are removed when 

 they are undeveloped, 

 which is before the bloom 

 opens, the purpose of this 

 operation will be defeated. 

 W. C. Bull and L. M. Gage 

 consider emasculation un- 

 necessary, but the fact 

 remains that pollen often 

 retains its fertility until 

 the pistil is ripe. In many 

 cases the top of the spike 

 is removed in order to con- 

 centrate the energy of the 

 plant on the flowers re- 

 maining. 



At the time the spike is 

 removed, the emasculated 

 flower is usually bagged, 

 in order to keep out bees. 

 The method of bagging 

 differs greatly. E. N. 

 Fischer uses a special hood consisting of a wire frame covered with 

 cloth, the wire projecting at the bottom and the hood closed by 

 a piece of tape fastened to the cloth. Much experimental evidence is 

 presented to show that cloth bags do not absolutely keep out foreign 

 pollen, so that for scientific results a waxed paper bag should be used, 



Fig. 30. AZALEA, A RUFFLED VARIETY 



