AN ENCYCLOPEDIA OF HORTICULTURE. 



429 



Nectary continued. 



Wild-flowers in their Relation to Insects " ; Kerner's 

 " Flowers and their Unbidden Guests " ; Darwin's " Cross 

 and Self Fertilisation of Plants," and various papers by 

 Kev. G. Henslow and others in the publications of the 

 Linnean Society, in the " Popular Science Review," and 

 elsewhere. 



In regard to the microscopic structure of the Nectary, 

 the nectar-producing tissue is usually made up of small 

 thin-walled cells that contain abundant protoplasm, a 

 nucleus, and cell-sap, rich in sugar. As a rule, the 

 Nectary shows a number of pores or stomata in the sur- 

 face layer of cells, and through these the Nectar is 

 poured on to the surface of the organ, whence it is 

 sucked up by the visitors to the flowers. There is 

 usually only a thin cuticle, or it is even absent practi- 

 cally in some plants, over Nectaries ; and frequently, the 

 Nectar soaks out through the thin walls of the cells to 

 the surface; but it may be retained inside the surface 

 layer, in cells so thin walled as to be easily pierced by 

 the proboscis of the insects suited to convey pollen to 

 the stigma. 



The Nectary has also been microscopically studied by 

 Mr. Cheshire, some of whose results and illustrations 

 (engraved from his own drawings on the wood), as 

 given in " Bees and Bee-Keeping, Scientific and Prac- 

 tical," are here, by permission, introduced. Taking a 

 recently- expanded blossom of the common scarlet Pelar- 

 gonium of gardens, which is selected because it is at 

 command, in most places, and at every season of the year, 

 we find, running down the flower stalk, and immediately 

 under the uppermost and broadest sepal, an enlargement 

 of the stalk itself, marked off by inconspicuous grooves, 

 and terminating in a small bulbous expansion a little 



FIG. 663. PELARGONIUM BLOSSOM AND NECTARY. 



A, Pelargonium Blossom s. Stigmas; e, Calyx; n, Nectary. B, 

 Calyx, with Ovary in cross section -n, Nectary; o, Ovary. 

 C, Blossom, side view, Corolla removed s, Stigmas ; a, Anther ; 

 c, Calyx. D and E, Cross Sections of Ovary, through lines a and 

 & of A. F, Stamen a, Anther. 



below the line b, Fig. 663, and which is often purplish 

 in colour. This is the Nectary ; and, if we now remove 

 the petals, and look at the calyx from the front, we 

 shall see into its opening (n, B). Making cross sections 

 through the lines a and b, we find the Nectary wider 

 above, as at D, and narrow below, as at E. A keen razor, 

 dipped in methylated spirit, will take off slices suffi- 

 ciently thin for microscopic examination under a cover 

 glass in water. Cutting "D longitudinally, so that the 

 Nectary is divided, and then removing a thin slice from 

 that which forms the upper part of the figure, and magni- 

 fying about 200 diameters, we find the outside to consist of 

 cnticular cells, carrying glandular hairs (gh, Fig. 664), 



Nectary continued. 



which secrete a resinous body of strong odour. The 

 cells on the opposite side of the section are not unlike 

 those of the external cuticle, although they constitute the 



FIG. 664. VERTICAL SECTION THROUGH TJ, Fio. 663, showing 

 (gh) Glandular Hairs. 



lining of the upper part of the Nectary, for they have here 

 no secretory function. Taking a section (see Fig. 665) 



FIG. 665. CROSS SECTION THROUGH E, FIG. 663^, Glandular 

 Hairs ; h. Hair ; cu, Cuticle ; no, Nectar Cells. Magnified 180 

 diameters. 



from the face of E, which lies in the line 6 (A, Fig. 663), 

 we discover the hairs and cuticle to be of precisely the 

 same character as those previously noticed ; but the lining 

 cells (nc) of this part of the Nectary are totally different, 

 extending inwards by almost pointed prominences. The 

 structure of the pointed cells is quite special, their con- 

 tents, as seen under high magnifying power, being 

 granular, especially near the cell-wall, which, at the 

 prominence, is excessively thin, and has, lying imme- 

 diately within it, a globular mass of highly refractive 



FIG. 666. NECTAR CELLS, Magnified 1000 diameters, showing 

 (n) Nectariferous Nucleus. 



protoplasm (n, Fig. 666), containing a distinct nucleus. 

 This is the active agent in accomplishing the secretive 

 act, and the surface of the cells here, in healthy plants, 

 and in proper conditions of the atmosphere, will always 

 be found to be coated with a layer of Nectar. 



To understand the presence of Nectar in a plant, and 

 the uses to which it is put, a short explanation is neces- 



