MODIFICATIONS OF THE CALYX 209 



of the hollow. For sepals are structures of the nature 

 of leaves (though without buds in their axils), and 

 leaves do not have other organs growing out of them. 



In a few plants the hollow at the end of the pedicel 

 is but shallow, so that the calyx stands only half 

 way up the ovary. The stamens and petals then 

 stand round, not on top of the latter, and may be called 

 perigynous (peri == round), or the ovary half -inferior. 



4. There are other considerable differences in the 

 sepals or calyx of different plants. The main purpose 

 being in most cases the protection of the young parts, 

 when the flower has opened, the sepals often fall off. 

 Thus in ARGEMONE, PAPAVER (poppy) and others of 

 that family, the calyx forms a hood over the flower 

 and is pushed off entire by the developing petals. 

 In DATURA the top half is pushed off in this way,. 

 the lower only remaining. 



In other plants the sepals persist as long as the 

 petals, and even remain on the fruit, as in the Guava. 

 PHYSALIS, the Cape-gooseberry, is peculiar in that the 

 calyx becomes larger and forms a sort of red bladder 

 round the fruit. 



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