480 



BEES AND FLO WEES. 



sep 



from the Italian variety Avitli its yellow fuzz, but both are even 

 still farther reiuoxed from the tropical bees, especially those of the 

 islands. Careful study is necessary to assign all these varieties to the 

 same t3'pe; there are thirty forms, most of which lune been taken b}' 

 man}^ zoologists for distinctive species. 



To-day hardly anyone disputes the adaptation of bees to food- 

 gathering in the floAvers, but the adaptation of the flowers to these 

 visitors remains an object of heated controversy. One of the schools, 

 headed by Darwin and Sir John Lubbock, exaggerates the influence, 



Avhile the other, M. Gaston Bonnier 

 and his pupils, denies its existence. 



Before entering upon this deli- 

 cate question let me recall the pas- 

 sage in which Sir John Lubbock has 

 (ixed its extent and portent. " Not 

 only,'' says he, " have the form and 

 the colors, the bright tints, the sweet 

 odors, and the nectar been gradually 

 developed by force of an uncon- 

 scious selection exercised by the in- 

 sects, but even the arrangement of 

 the colors, the shape, the size and 

 the position of the petals, the rela- 

 tive position of the stamens and 

 pistil, are all determined by the 

 visits of the insects, and in such a 

 way as to assure the great object 

 (fertilization) that these visits are 

 intended to effect." 



In his beautiful work on the nec- 

 taries, Gaston Bcmnicr has fur- 

 nished luunerous irrefutable argu- 

 ments against tlie theory that that 

 nectar is an adaptation to attract 

 insects. According to this author the nectaries are organs of reserve 

 where the cane sugar, dissolved in the cellular juice, is elaborated 

 and stored. As night falls, closing the air-stomata and arresting 

 the chlorovaix)rization, the emission of water vapor by the plant is 

 replaced by a sort of sweating, which conies slowly from all points of 

 the surface and the nectaries in the form of little drops more or less 

 rich in sugar. Thus the drops of nectar have the same origin as the 

 water given forth by the water-carrying stomata. They are the result 

 of a stoppage in the transpiration and do not present any jjeculiar 

 character other than that of having traversed organs rich in s^c- 



Ptg. 8.— Nectaries and exudation of nec- 

 tar, much enlarged. (After Gaston Bon- 

 nier. ) 



1. Longitudinal cross section of the ,Salcia 

 huitduifolia: r((/, insertion of the calyx; 

 (■<ii\ insertion of the petals; «, nectaries 

 with carpels; /c, vessels leading to car- 

 pels; fn, vessels leading to nectaries, ri. 

 Longitudinal cross section of Auhrictia 

 cohaunae: sej), sepals; ef, stamens; ii, n, 

 nectaries; </, drop of nectar falling into 

 reservoir. 'H. Nectary of a peach flower, 

 showing the nectar (g) which accumu- 

 lates in the chamber (c) of a stoma. 



