ANGIOSPERMS. 
545 
portion of the stamen remains very short, while the secondary filaments lengthen 
considerably and subsequently present the appearance of a tuft springing from the 
receptacle, the true nature of which can only be ascertained by the history of its 
development. If, on the contrary, the primordial basal portion lengthens, as in 
Fig. 367.— Development of the flower oi Hypericin perforaitmt ; I young flower-bud in tlie axil of the bract B, with its 
two bi acteoles bb, s the sepals, p first -indication of the petals ; // middle part of a somewhat older bud, / rudiment of the 
ovary, a, a, a the three stamens with the rudiments of their branches arising as protuberances ; /// a flower-bud of nearly 
the saiKie age as in //, but seen from the side, s a sepal, a a the stamens,/" the ovary ; JV and F flower-buds in further 
stages of development, the letters indicating the same as in/, //, and ///; i, 2, 3 ovary in various stages of development cut 
through horizontally. 
Calothamnus, the whole stamen is easily recognised as branched even in the mature 
condition. 
Of no less importance for understanding the entire plan of structure of a 
flower, and especially the relations of number and position w^hich actually occur, 
Fig. 368.— Development of the androecium of Ctccurbäa Pepo (after Payer) ; in all the figures the simple stamen is to the 
right, behind and to the left two double ones. The anthers grow vigorously in length and form vermiform coils. 
is the cohesion of stamens which grow side by side in a whorl. In Cucurbita, 
for example, there are, in the earliest stage, five stamens, but at a later period only 
three are found, two of which are, however, broader than the third ; these are each 
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