ALLUREMENTS OF ANIMALS FOR THE DISPERSION OF POLLEN. 



177 



without the development of any special expansion. The nectaries are unusually 

 well-developed on the perianth of the American Uvularia grandiflora, in the 

 numerous species of Fritillaria, and especially in the Crown -Imperial, often 

 cultivated in gardens under the name of Fritillaria imperialis. Each of the six 

 perianth-leaves in these plants exhibits on the inner side near the thickened base 

 a circular, sharply-defined depression in which sparkles a large drop of honey. 



Honey is seldom secreted by the calyx. 

 The best examples are the coloured, ex- 

 panded and fleshy calyx of the various 

 species of the genus Cuphea and of the 

 Nasturtium (Tropceolum). The species of 

 the last-named genus have a calyx from 

 whose upper portion a long spur projects. 

 Honey is secreted in the narrowed lower 

 portion of this spur, and indeed so abun- 

 dantly that it sometimes reaches to the 

 mouth. 



And now we come finally to the nec- 

 taries in the region of the corolla. Those 

 developed at the base of the flower as 

 well as on the carpels, stamens, perianth- 

 leaves, and calyx, though strikingly varied, 

 are poor in comparison with the wealth of 

 forms which are shown in the petals. In 

 this book it is impossible to give an ex- 

 haustive description of these structures, 

 and it must suffice to group together 

 generally the most striking forms and 

 those best fitted to illustrate the processes 

 hereafter to be described. In the corollas 

 of the Mulleins, especially in those of 

 VerhascuTYi Blattaria and phoeniceuTn, the 

 secretion of honey takes place on the large, 

 lower petal in the form of numerous 

 drops scattered over the middle of the leaf. 

 Each drop comes from a stomate, and, therefore, when the flower opens this leaf 

 looks as if it were studded with dew. But this seldom happens. More usually 

 the small drops flow together, and then a large drop appears in some special spot. 

 In the twining Honeysuckles {Lonicera Gaprifoliura, etrusca, grata, implexa, 

 PericlyTnenv/m, &c.), in the Bearberries (Arctostaphylos alpina and Uva-ursi), in 

 Allionia and Grucianella, in a species of Winter-green {Pyrola secunda), as well 

 as in numerous other plants, honey is secreted in the manner just described in the 

 lowest part of the tubular or bell-shaped corolla. In the Alpine Roses (Rhododen- 



Fig. 248. — Narcissus (Nardesus Pseudonarcissus). i The 

 complete flower. 2 Xhe flower cut longitudinally. 



62 



