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upper internode with the fiower at the top, still grows 

 considerably in length. For this the présence of the flower 

 is absolutely necessary, The upper portion of the stem is 

 arrested in growth and gradually dies off as soon as the 

 flower is eut off. 



Example: a. flower présent; 6. flower removed. Only the 

 upper internode measured. 



From the following measurements the significance of 

 the varions floral parts may be scen : 



a. perianth removed. 

 h. stamens removed. 

 c. pistil removed. 



Although removal of each of the individual whorls of 

 organs partly suppresses the growth of the upper internode, 

 yet It is seen that the petals hâve the greatest influence 

 hère. The above is only an example chosen from several 

 concordant measurements. 



Finally somc observations were made with Crocus vernus 

 Ail. Since the ovary lies fairly deep hère, hldden in the 

 tube formcd by the green leaves and the bracts round 

 them, plants that had been eut open had to be used for 

 the measurements, in which the flower was laid bare 

 over its full length. For this purpose flowers were chosen 



