406 



HUTCHINSON'S POPULAR BOTANY 



FIG. 503. FLOWER OF Kalmia latifolia. 



In the first condition the stamens are bent back and the 



anthers held fast in pouches of the corolla. 



cases their purpose is purely an 

 aesthetic one. The Opium and 

 Common Red Poppies, for example 

 (Papaver somniferum and P. rhoeas), 

 have no honey, and yet they are 

 strikingly marked ; and in many 

 labiate flowers and Saxifrages (e.g. 

 Saxifraga officinalis, fig. 484) the 

 marks are so small as to be hardly 

 visible, at a few paces at least, to 

 the human eye. But, of course, if 

 their presence is related to insect 

 visitors they are only intended to 

 be seen at short range when the 

 insect is actually on the flower. 



We come now to Nectar. Of all 

 the attractions which flowers hold 

 out to insect visitors, this is un- 

 doubtedly the chief. Nectaries are 

 usually, though not always, situated deep down in the flower ; and they 

 present a variety of forms. In some flowers they have the appearance of 

 small fleshy warts and pegs ; in others they are grooved ; in others ring- 

 shaped ; and in the fourth case, hollowed out like spoons or shallow cups. 

 These are the most common forms. The nectar itself " is not," says 



Professor Trail, "identical with 

 honey, although, as furnished by 

 many plants, it is the material 

 from which bees make the latter. 

 Analysis has shown the sugar of 

 nectar to be, very generally, cane- 

 sugar, while that of honey is grape- 

 sugar, consisting of dextrose and 

 levulose in equal proportions. The 

 conversion of the cane-sugar is 

 brought about by an admixture of 

 salivary secretion at the time the 

 nectar is sucked up. This conver- 

 sion has been well made out in 

 the case of bees ; and since larger 

 animals and man are known to con- 

 vert cane-sugar into grape-sugar as 

 FIG. 504. FLOWEB OF Kalmia latifolia. an initi al process in digestion, it is 



A bee in search of nectar causes the anthers to spring from Probable that butterflies and moths 



the pouches and dust the visitor with poiien. effect the same changes as the bee." 



