Xrrtar Aj>j)nirifns of Yacca. 



91 



These interesting facts, which I have fully verified, show that 

 nectar-feeding insects seek it not aI)Out tlie stigma, hut at the 

 l)ase of the stamens or of the petals, whether within or without. 

 In short, the nectar in these Yucca flowers has no value in i)ol- 

 lination, and Pronuha, in collecting the pollen and transferring 

 it to the stigma, finds no food compensation, a conclusion which 

 is confirmed by a study of the minute structure and internal 



Fii;. — Neetar apparatus of Yueoa: a, loiifritudinal ser-tiou of pistil, with duct {d) and 

 gland (g); 6, cross-section aVjout middle, sliowing same parts ; c, still more enlarged 

 cross-section of nectar apparatus; e, structure of septal gland— after Trelease; k, longi- 

 tudinal section of top of pistil, showing stigm.atic tube (s) ovarian cell {oc), ovule (o), 

 funiculus (/), placenta (p), and fibro-vasciilar tissue {fv). 



anatomy of the motli, which indicate that the tongue })roper, 

 though strongl V developed, has to a great extent, if not entirely, 

 lost its function as a sucking organ, and that the alimentary 

 canal is practically functionless, being aborted before reaching 

 the anus. This defunctionization, if I may use the term, of im- 



