THE STIUXTURE OF THE FLOWER 327 



calyx. This produces the calvx cu}), wliitli is very well seen in 

 the Rose. The ^i^yna^ceuin is enclosed in the calyx aip, or, as 

 it is sometimes called, the rcccptacuhir cup, and the sttunens, 

 petals, and free parts of the sepals arise from the e<l^e of it. 

 This kind of flower is called peri gi/ nous, while the simpler ty|)c, 

 in which the receptacle is more or less conical, is calletl 

 h?/poff}/m)us {cf. Ruttercup, Text-fi<;. XXVI.). 



As a further development, the gyna'ceum may fuse 

 completely with the calyx tube, so that all the floral part« 

 appear to grow on the top of the ovary (cf. CrcK'Us, Text- 

 fig. XXX., and Groundsel, Text-fig. XXIX). The flower is 

 then said to be cp'ifrijiions, and the ovary iiifcriur. 



Resides the floral parts which we have mentioned, sj)ecial 

 structures called nectaries occur in some flowers. These take 

 various forms, but agi'ee in one essential feature — namely, that 

 they secrete honey. In many flowers the nectaries are mo<lified 

 stamens, as in the Globe-flower (p. 207), where they are horn- 

 shaped structures. In this case the modified stamen both secretes 

 the honey, and forms a receptacle to hold it. In the Pansy, on the 

 other hand (Text-fig. XV.), processes from two of the stamens 

 secrete the honey, which drops into a spur-like receptacle, 

 hollowed out of the base of the front petal. In the Lesser 

 Rutterfly Orchid ('L'ext-fig. XI., 1), one of the perianth memlx'rs 

 is spurred like the Pansy ; but here it is the tissue of the spur 

 itself which secretes the honey. In the Ruttercup (Text-fig. 

 XXVI., 2), honey oozes out from a patch of glandular tissue 

 concealed behind a little scale at the base of the {)etal. 



Starting from such a flower as the Ruttercup, there seem to 

 be several lines along which evolution may procecnl. One of 

 the most important steps involves the union of the jK'tals — that 

 is to say, polypetaly is replaced by gamoj)etaly. On the other 

 hand, the plant, instead of becoming more higlily evolvi-d in 

 regard to the corolla, which aims at the attraction of inserts, 

 may decide to dispense with it altogether, or to reduce it to 



