LIFE HISTORIES OF FAMILIAR PLANTS 



carpels are essential, although, as ^Ye have seen 

 in the case of the S3^camore flowers, they need 

 not necessarily be in the same flower. One flower 

 may have sepals, petals, and stamens, but no 

 carpels, when it becomes a male flower ; another 

 flower may have sepals, petals, and carpels, but 

 no stamens, when it becomes a female flower. 

 In such cases the pollen is generally conveyed 

 from the male to the female flower by means 

 of the insects that visit them alternately. The 

 simplest and most primitive kind of flower con- 

 sists of a single carpel or ovary that produces 

 a seed, or a single pollen-producing stamen, with- 

 out any sepals or petals around it, and this is 

 what we have in the case of the arum. The arum 

 possesses many flowers, botanically speaking, but 

 it can scarcely be said to possess anything worthy 

 of the name in its popular acceptation, although 

 the inflorescence as a whole partly atones for its 

 delinquencies. 



If, now, we look carefully at Fig. 29 (Plate 19), 

 we shall observe that, at the lower part of the 

 purple club, in the area where ths midges are 

 entrapped, there are three kinds of small bodies. 

 Lowest of all are pale-coloured roundish objects ; 

 each of these consists of a single carpel containing 

 an embryo seed. Above these are some smaller, 

 curious, purple-coloured knobs, which when mature 

 burst open and shed quantities of yellow pollen 

 dust. From what I have previously said, it is 

 plain, then, that we have here two groups of the 

 simplest of flowers, just a single stamen, or a single 



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