296 



THE STRUCTURE OF FLOWERS. 



BcecJcia diosmcefoUa ; * but as they grew on the interior of 

 the wall and not on an axile placenta, as is the normal con- 

 dition in the Myrtacece, I expect that it was due to the 

 staminal vascular cords branching off and coming out of the 

 tissue within instead of at the summit of the hollow recepta- 

 cular tube, the carpels being more or less arrested. A not 

 uncommon instance is to find the pistils of Willows with 

 open ovaries and bearing one or more anthers on the margins 

 (Fig. 78, a). I have met with a" similar occurrence in 

 Ranunculus auricomus (Fig. 78, &). Pistils of other flowers 



<v 



Fig. 78. — Stameniferous carpels of AVillow 

 (.a) and Ranunculus auricomus (,6). 



Fig. 79. — o, Petaliferous placenta? of Car- 

 (lamine pratensis ; b, of RhodUxUndron. 



in a similar waj, 



as 



have been known to bear anthers 

 Chamoerops humilis, Primus, f etc. 



Pollen within ovules has been met with occasionally, as 

 in Passiflora and Bosa arvensis.X 



In some members of the Cruciferoe, as Cardamine pratensis 

 (Fig. 79, a), round pods are formed instead of the usually 



* Teratology, p. 184. Possibly the ovaiy was entirely absent, and the 

 stamens would then be growing on the interior of a closed receptacular 

 tube, just as carpels grow upon the inside of the hip of a rose. 



+ See Weber, Verhandlung des Nat. Hist. Vereines der Preuss Rhein- 

 und Westph., 1860, p. 381. 



X Teratologrj, p. 185. 



