294 



THE STRUCTURE OF FLOWERS. 



attributes of the stamen and of the pistil in the same organ, 

 the pollen is formed in the upper or inner surface of the leaf 

 organ, while the ovules arise from the opposite surface from 

 the free edge." Begonia is a genus which is peculiarly liable 

 to produce malformations in the stamens (Fig. 76).* Rosa 



Fig. 75.— Ovuliferous anthers of 

 Sempervivum (afier Masters). 



Fig. 76.— Stigraatiferous and ovuliferous 

 stamens of Begonia. 



arvensis t affords a case in which the ovules were borne by 

 the anthers, and then they themselves produced pollen. In 

 these cases, where the anthers are ovuliferous, the connective 

 is often more or less stigmatiferous, as in Begonia (Fig. 76), 

 which shows various degrees of metamorphosis in this way ; 

 but the anthers may sometimes be stigmatiferous, as in 

 Poppies, X or styliform as well, as in Bamboos. § 



The complete substitution of carpels for stamens occurs 

 in many plants, as in Malus apetala,\\ Tulips, etc., and is 

 extremely common in Wallflowers,'|[ while it is by no means 

 an uncommon occurrence to find male plants of normally 

 dioecious or monoecious character bearing female organs, 

 though perhaps in these cases it is often an addition, rather 

 than a substitution of one organ for another. 



♦ See Journ. of Lin. Soc. xi. 472; Bot. Zeit. (1870), vol. xxviii., 

 p. 150, tab. ii. 



t Journ. of Bot., 1867, p. 318, tab. 72. J Teratology, p. 304. 



§ Col. Munro, Trans. Lin. Soc, vol. xxvi., p. 7. 



(I Poiteau et Turpin, Arhr. Fruit., t. xxxvii., referred to by Moquin- 

 Tandon, Teratologic, p. 220. 



% Called " Rogues " by the market -gardeners, as the corolla is want- 

 ing or green. See Ann. des Sci. Nat., 5 ser., xiii., p. 315, pi. 1. 



