PHYLLODY OF THE FLORAL WHORLS. 



805 



Pistils whicli have reverted to a more or less foliaceous 

 character bear ovules which often become foliaceous as 

 well ; and then a not uncommon procedarc is the develop- 

 ment of a cup-like structure, probably composed of the two 

 ovular coats, on an elongated stalk, with a rudimentary 

 nucellus within, but more or less perfectly free from it ; or 

 it may not exist at all. 



The late Professor Henslow described a monstrous con- 

 dition of Mignonette with figures of ovules in this condition.* 

 They were sometimes 

 replaced by minute 

 leaves (Fig. 85, c) ; or 

 else in the place of 

 each was a cup-like 

 structure, elevated 

 on a long stalk, with 

 an egg-like nucellus 

 within, but quite free 

 from it. He likened 

 it to the theca of a 

 moss with its central 

 columella. Comparing these two modifications, represented 

 by Fig. 85, a and h with c, — or, again, those of Fig. 86, a 

 and h, — the interpretation seems to be that the fibro-vascular 

 cord passing up the funicle of the ovule becomes a petiole, 

 and its prolongation constitutes the mid-rib. The secundine 

 and primine with intermediate tissue become the blade, as 

 seen in the foliaceous states of ovules, and constitute the 

 " cup " when they assume that form. 



A similar process, I think, quite explains the origin of 

 the foliaceous processes of the stamen of JatropJia, repre- 

 sented by Fig. 84. The entire stamen is, of course, really 

 * Trans. Camh. Phil. Soc, vol. v. 



Fig. 85. 



-Foliaceous and metamorphosed ovules of Migno- 

 nette (after Prof. J. S. Henslow). 



