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swelling occnrrin^ at the point whore the bracts and flower-stalk 

 are implanted, so I hat this zone also has no importance for the 

 growth of the ])arts nnder it. Also stems of Gdlanthus and Mnr- 

 cissK.'i, cnt in the basal part and hence separated from the bulb, 

 or even parts of them, if (hey were taken fi'oni plants with their 

 tlower-bnds still closed, continue to grow vigorously whether the 

 flower-bud be present or not. 



Tulipa (iesnerlana L. siiows sometliing diflcrent again. Hei'c the 

 floAver is born by a leafed stem; the inlernodes which arc phiced 

 near the base stop growing sensibly towards the time that the (lower 

 becomes visible from the outside and is about to open. At this 

 stage, however, the upper intcrnode with the flower at the top, 

 still grows considerably in length. For this the presence of the 

 flower is absolutely necessar\'. The upper portion of the stem is 

 arrested in growth and gradually dies off as soon as the flower is 

 cut off. 



Example: a. flower present; /;. flower removed. Only the upper 

 intcrnode measured. 



From the following measurements the significance of the various 

 floi-al parts may be seen : 



Although removal of each of the individual whorls of organs, partly 

 suppresses the growth of the upper intcrnode, yet it is seen that 

 the petals have the greatest influence here. The above is only an 

 example chosen from sevei-al concordant measurements. 



Finally some observations were made with Croats vernus All. 

 Since the ovary lies fairly deep here, hidden in the tube formed by 



