THE MAKING AND UNMAKING OF FLOWEKS. 



121 



hcloic the pistil. They are then said to be " hypogynous," i.e. under the 

 pistil. 



The next step is to see how this lateral expansion can grow upwards 

 and form a cup, in which the pistil is left behind at the bottom, while the 

 sepals, petals, and stamens are carried up to the rim of the cup. This is 

 the case with the Plum, Apricot (fig. 46), and other species of the genus 

 Prunus. In the Rose (fig. 47) it forms the "hip;" but this contains 

 several free carpels instead of one only, as in the Cherry. 



Yet a further result has occurred. In the genera Primus and Rosa 

 the carpels are perfectly free in the interior of the recejjtacidar tube, as it 

 is called. But in the Apple (fig. 48) and Pear, Medlar, Quince, and Cur- 

 rant, the carpels have become wielded with the thickened tube, so that 

 the inner epidermis of the latter, and the outer one of the former, are 

 arrested, and the middle layers of both become amalgamated into one 

 mass, which constitutes the edible part of the Apple, &c. It is the inner 

 epidermis of the carpels which constitutes the core.* 



In the illustration of the Apple, the remains of the sepals and 'stamens 

 (the petals having fallen off) on the top or " eye " indicate the fact of 

 the calyx being, as it is called, " superior "t and the fruit "inferior." 

 Similarly, in the figure of the flow^er of Currant (fig. 49) it will be seen 

 how the large calyx is spread out like a dish above the ovary, the smaller 



petals alternating vdth them ; then the stamens follow in front of the 

 sepals. The lining of this dish is the honey-secreting surface of the 

 expansion of the receptacular tube, which is adherent to the ovary below. 



The next features to be noticed are described as "regularity" and 

 irregularity " of flowers. The first is applicable to each whorl, and 

 means that all its parts are exactly alike. Thus a Buttercup, a Columbine, 

 a Rose and a Primrose have every whorl regular. But if the parts of a 

 whorl are not all alike in shape, &c., then such a whorl is irregular ; and 

 as it gives a peculiar appearance to the whole flower, the flower itself is 

 usually said to be irregular (figs. 50, 51). 



It is here where the influence of the irritations set up by insects 

 become most apparent. 



The first coincidence observable is that resfular flowers are almost 

 always terminal ; and if lateral they stand away from the main stem 

 sufficiently to allow of their being visited from all points, and so they 

 remain regular. Thus in a Geranium there are five honey-glands situated 

 symmetrically round the base of the flower on the receptacle (fig. 42). 



* The double line in fig, 48 indicates the line of junction between the recepta- 

 cular tube and carpels. 



t These terms are only applicable to the calijx and ornnj. In a Buttercup the 

 ovary is "superior" and the calyx "inferior," as there is no receptacular tube 

 adherent to the ovary. 



Fig. 48. — Vertical section of Apple. 



Fig. 40. — Vertical section of flower of 

 Currant. 



