12 NIGHT FLOWERS. [CHAP. 



that scent is an advantage to flowers by attracting 

 insects. No wind-fertilised flowers are scented. On 

 the other hand, while colour is as useful as scent by 

 day, at night it is of course less easily perceived. 

 Hence night flowers are specially odoriferous, and 

 there are some such as Hesperis matronalis, Silene 

 mitans, &c. which are very sweet in the evening 

 and yet emit little or no odour by day. 



The honey is secreted, sometimes by one part of the 

 flower, sometimes by another ; and great variations 

 may be found in this respect even within the limits of 

 a single order. Thus in the Ranunculaceae the honey 

 glands are situated on the calyx, in certain Paeonies ; 

 on the petals, in buttercups and hellebore ; on the 

 stamens, according to Miiller, in Pulsatilla ; and on 

 the ovary, in Caltha. 



The real use of the honey in flowers, indeed, now 

 seems so obvious that it is remarkable to see the 

 various theories which were entertained on the subject. 

 Patrick Blair thought it absorbed the pollen, and thus 

 fertilised the ovary. Linnaeus confessed his inability 

 to solve the question. Other botanists considered it 

 was useless material thrown off in the process of 

 growth. Kriinitz even thought he had observed that 



O *-> 



in meadows much visited by bees the plants were 

 more healthy, but the inference he drew was that the 

 honey unless removed was very injurious, that the bees 

 were of use in carrying it off. Sprengel was the first 

 to show that the real office of the honey is to attract 

 insects, but his view was far from meeting with general 

 consent, and even so lately as 1833 were altogether 

 rejected by Kurr who came to the conclusion that 



