AMARYLLIDEAE 



435 



its thickened greenish tip. It may be inferred that secretion of nectar takes place 

 in the parts mentioned. 



It thus appears necessary to examine once more the whole flowers of Leucojum 

 vernum L., and also of Galanthus nivalis Z., sections of which I had treated with the 

 reagents mentioned. 



Visitors. In gardens at Kiel Knuth observed the honey-bee as a visitor and 

 pollinator of L, aestivum, but could not discover the manner in which it worked. In 

 the Berlin Botanic Garden Loew noticed the bee Podalirius acervorum Z. j, po-cltg. 



865. Galanthus L. 



As Leucojum. Nectar-guide only on the tips of the petals. 



2701. G. nivalis L, (Sprengel, 'Entd. Geh.,' pp. 177-80; Herm. Miiller, 

 'Fertilisation,' p. 589; Kerner, 'Nat. Hist. PI./ Eng. Ed. i, II, p. 176; MacLeod, 

 Bot. Jaarb. Dodonaea, Ghent, v, 1893, 

 p. 315; Stadler, 'Beitrage'; Delpino, 

 Bot. Centralbl., Cassel, xxxix, 1889, 

 p. 124; Kirchner, 'Flora v. Stuttgart/ 

 p. 73; Knuth, 'BloemenbioUBijdragen/ 

 Bot. Centralbl., Cassel, Ixxiv, 1898.) 

 The white flowers of this species are 

 homogamous. Each of the short petals 

 possesses a yellow-green, lunate, trans- 

 verse band outside, and a number of 

 green, longitudinal lines inside as nectar- 

 guides. Hermann Miiller and Kerner 

 state that the nectar is secreted in 

 the grooves : I have examined transverse 

 sections of the latter under a microscope, 

 but could find no secretory cells there. There is a layer of strongly projecting 

 cells externally, bearing colourless protoplasm and causing the white colour of the 

 outside; beneath this is found assimilation-tissue. The upper and lower sides of 

 the petal are connected by parenchymous mesophyll with small vascular bundles. On 

 the lower side there is a row of thinner, air-containing cells, through which the 

 assimilation-tissue is visible. In the indentations there is, however, no chlorophyll 

 to be found in the posterior cells, which causes the alternate green and white 

 streaking internally. Stadler considers the disk surrounding the style as a nectary 

 without free secretion. Delpino thinks that the cordate green spots and the 6-7 

 green, longitudinal lines on the inside of the petals are nectaries. There is also 

 a small quantity of nectar produced by a circlet of very small pits at the base of 

 the style. Sprengel supposes the petals to be both nectar-receptacles and glands ; 

 ' They do not, however, secrete nectar on the whole of their inner surface, but 

 only in the middle as far as they are green.' 



In unopened snowdrops brought to my laboratory at 8 a. m. I could find no 

 free nectar. As the flowers opened after some time in consequence of the warmth of 



F f 2 



Fig. 393. Galanthus nivalis^ L. (from nature). A. 

 Lateral view of a flower, after removal of half the perianth. 

 B. Do., with ovary in longitudinal section, after removal 

 of the perianth and three stamens. C. A stamen^ further 

 enlarged, with dehisced anther. a, anthers; p^ petals 

 with nectar-guides ; s, stigma. 



