COHESION AND SUPPRESSION. 



259 



interesting transitional example was seen in Liliurn 

 candidum which proved this. The different ivhorls, 

 as described in a previous section, were rearranging 

 themselves during the tendency towards spiral phyllo- 

 taxis ; two members of the perianth, a sepal and a 

 petal, had become united, as also two stamens, one 

 from each whorl ; of the three carpels two were 

 partially coherent, representing a transition to two 

 carpels. 



Suppression. — In the normal course of floral evolu- 

 tion, as Celakovsky has so well pointed out, great 

 numerical reduction in the gynceceum has taken place, 

 in fact much more so than in any of the other 

 whorls. This is well seen in the Prunese section of the 

 Rosacese and in the Leguminosse. 



The pleiomerous gynceceum may become abnor- 

 mally reduced. Masters mentions a flower of Papaver 

 Rhoeas which was evidently provided with four carpels 

 only. 



Moquin Tandon states that a bramble (Bubus) pro- 

 duced an etaerio with but a single drupelet, resembling 

 a small cherry. 



The pistil of Aconitam, Delphinium, Nigella, and 

 Pasonia has doubtless been evolved from one with 

 many carpels, as in the majority of the Ranunculacese ; 

 in these meiomerous pistils reduction still frequently 

 occurs abnormally. 



In the flower of Tulipa persica previously described, 

 which had a 5-merous perianth and androecium, the 

 pistil was bicarpellary. 



A long list of such instances of reduction need not 

 be cited ; they are sufficiently numerous. 



A rather striking one may be mentioned in the 



2- merous orchid- and Ins-flowers, where the normal 



3- merous ovary loses a member of its whorl. Also in 

 the flower of Odontoglossam crispum in which disrup- 

 tion of the column and petalody of some of the 

 stamens occurred, the ovary and stigmas appeared to 

 have completely vanished. 



