CHAPTER XXIX. 



RETROGRESSIVE METAMORPHOSES. 



The Pistil. — Commencing with tlie pistil, there may be 

 changes in the ovary, ovules, style, and stigmas, separately 

 or collectively. Instead of one or more 

 ovules, a pistil may be formed within 

 an ovary, as sometimes occurs in Wall- 

 flowers, Grapes, Oranges, etc.* A sin- 

 gular instance is described by Dr. 

 Masters f of a Carnation, " the placenta 

 of which bore not only ovules but also 

 carpels, the latter originating in a per- 

 verted development of the former ; so 

 that many intermediate stages could be 

 traced between the ordinary ovule and 

 the ovary. Some of these carpels, thus 

 derived from ovules, themselves bore 

 secondary ovules on a marginal pla- 

 centa " (Fig. 77, a, carpel and section), the secundine, how- 

 ever, being the only part developed (b). 



Stamens within an apparent ovary have occurred in 



* Teratology, p. 182. 



t L.c, p. 267. Perhaps the supposed " ovule within an ovule " may 

 have been the nucellus only, more or less free from the secundine. 



Fig. 77. — Carpels and ovules 

 on placenta ot Carnation 

 (after Masters). 



