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fairly large. Not only do different plants behave very unequally, 

 l)ul the same is noticed on comparison of the various inflorescences 

 of the same plant. 



Without careful inspection one gets the impression that the flowers 

 of this Dendroh'mm are solitary in the axils of the leaves ; closer 

 observation, however, shows that these axils do not contain a solitary 

 flower, but an infloi'escence, of which the axis remains extremely 

 short and generally only a single flower opens at a gixen time. 

 Sometimes, howevei-, two open flowers ai'e found together in the 

 inflorescence, very rarely even three. Now when careful notes are 

 made as to which inflorescences of a plant produce open flowers 

 at a given flowering period and subsequent flowering data are 

 compared with these, it is found, that in some cases a flower opens 

 in the inflorescence at each lime of flowering and that at other 

 times it is left out one or more times. Nor is any order discernible 

 in the combination of intlorescences, which bear open flowers at 

 successive flowering periods. All this was of course to be expected 

 on the assumption that the unfolding of the flowers depends on the 

 presence of buds in a definite developmental stage at the moment 

 that favourable external conditions occur. 



The question arises, whether a closer examination of the buds 

 gi\'es any indication as to the nature of this stage of development. 

 The inllorescenco is found to arise in the axil of a sheathing leaf 

 without lamina. The young bud is completely surrounded by the 

 sheath and the breaking through of this sheath is evidently diflicult. 

 Each bud consists of a number of bud scales and the rudiments 

 proper of the flower. These bud scales completely surround the 

 interior of the bud and j)resent ihemsehes as closed sheaths, which 

 are hard and little permeable — so lillle, that a bud which has lain 

 in alcohol for some days, does not show internally a trace of tliis 

 liquid. When the interior of the hud has once broken through these 

 sheathing scales, the latter become fibrous and resemble strawy since 

 hardly anything remains beyond the vascular bundles. Every floral 

 bud is generally cut off from the outside world by two of these 

 scales ; these must be broken through before the flower can open. 

 As long as the bud is not longer than 4 — 5 m.m. it remains between 

 these sheaths ; at this stage all the floral parts are easily recognized, 

 although their dimensions are small; oidy the spin' is not yet \isil)le. 

 When the scales are broken through a sudden extension of all the 

 floral parts takes place and after a few days the flowers have opened. 

 Hence just before the flowering a number of buds are found, having 

 a length of 4—5 m.m., while immediately afterwards this number 



