172 AN ERRATIC IVY. 



the tufts of aerial roots. It is not easy to decide on the claims of 

 this to be a native here. On the one hand, there is no geographical 

 improbability in its being so, its hitherto known localities being 

 Tavoy and Mishmi ; neither is it a fern likely to be intentionally 

 introduced, as it has no beauty to attract collectors. But the 

 localities here are neither of them wild ones, and are in places 

 extremely well-known and very long under cultivation ; moreover, 

 the search for ferns in Ceylon has been very keen. On the whole, 

 I am rather inclined to believe an accidental introduction at no 

 very distant date. 



AN EEEATIC IVY. 

 By Maxwell T. Masters, M.D., F.K.S. 



The normal flowers of the Ivy, Hedera Helix, have perigynous 

 or almost epigynous stamens, a partially " inferior " ovary sur- 

 mounted by a dome-shaped disc continuous with, and which is indeed 

 a mere expansion of, the base of the styles, as in the Umbelliferae. 

 The interior has three or more cavities with an axile placentation 

 and a single ovule pendulous from the upper and inner corner of 

 each of the ovarian compartments. Some flowers obligingly com- 

 municated by Mr. T. E. Archer Briggs, from the neighbourhood of, 

 Plymouth, presented a very different structure, and showed devia- 

 tions from the natural conformation, such as have not to my 

 knowledge been previously recorded. The "receptacle" was 

 turbinate as usual, giving off, from its upper border, sepals and 

 petals of the ordinary character and arranged in the ordinary way. 

 The stamens were hypogynous and emerged from the receptacle 

 around the base of a fleshy green cup occupying the centre of the 

 flower. This cup was more or less fluted, and bore upon its free 

 edge a ring of anthers of a reniform shape and curled over the 

 margin of the cup. There was no trace either of styles, placentas, 

 or ovules ; but within the cup the axis terminated in some in- 

 stances in a small point, in other cases in a shoot bearing an 

 imperfectly developed flower destitute of sepals and petals but 

 having a variable number of hypogynous stamens and a free ovary 

 with three isolated styles. These appearances are represented in 

 Fig. 1, made for me by Mr. Worthington Smith, but it should be 

 stated that the conditions were slightly different in detail in different 

 flowers. 



The explanation seems to be that the carpels were congenitally 

 united into a tube ; that they remained free from any adhesion with 

 the receptacle externally ; that their margins were not infolded ; and 

 that no ovules were developed from them, but that anthers or male 

 sporangia were developed from the free edge at the place where 

 styles and stigmas would, under ordinary circumstances be de- 

 veloped. The ovarian character of the anther-bearing cup was 

 further ascertained by my friend Eev. Prof. Henslow, who traced 

 in the anther-bearing cup the vascular cords corresponding to those. 



