54 SOUTH AFRICAN FLOWERING PLANTS. 



of the flower (sepals, petals, and stamens) appear to 

 spring from the top of the ovary of the pistil. This is 

 well seen in Fig. 10, which is a vertical section of the 

 flower of Mesemhrian'themum ; the interpretation, how- 

 ever, is as stated. In these cases botanists speak of the 

 calyx as being suijcrior and the ovary inferior, while 

 the petals and stamens are described as epigynous} 



Honey-glands, etc. — A fourth peculiarity in the 

 majority of flowers is the provision for supplying honey 

 or " nectar " to insects. This is done by a superficial 

 group or layer of " cells," forming a gland, which pours 

 out this sweet fluid. It may occur on any part ; but it 

 is always just where the insect can most readily reach 

 it with its tongue or proboscis. 



A few examples will illustrate this. In Ahu'tilon 

 and Hibiscus it is the base of the calyx which 

 secretes it. A difference in the appearance of 

 the surface at that place is easily perceptible to the 

 eye if the calyx be turned backwards. The English 

 Lime tree has little boat-like sepals, each of which is 

 full of honey, much sought after by bees. In South 

 Africa, Greiv'ia, of the same family as the lime 

 (Tiliacece), has a nectary at the base of the petals, just 

 as in Ranun' cuius. 



In some few plants the stamens secrete it. 



* I.e. " upon the ovary." In all flowers in which there is no such 

 adherent receptacular tube the calyx is "inferior" and the ovary 

 " superior " (Figs. 5, 8, 9). 



