THE INFLORESCENCE, AND THE FLOWER 



235 



parts which comparison with allied plants would show as actually 

 present. Sometimes those parts are represented by vestigial remains, 

 marking the position which those parts should hold, though they do 

 not come to functional maturity. A good case of a vestigial stamen 

 (st.) is seen in Scrophularia (Fig. 1S3). 



Meiomery may appear in an}' of the floral parts ; often it is seen in several of 

 them in the same flower. A complete whorl may be absent : for instance the 

 corolla in the Pearl- Wort (Sagina apetala) in the Pink Family, or Glaux among 

 the Primroses : or one of the whorls of stamens may be absent, as in the Prim- 

 rose. The most marked examples in the androecium are related to increasing 

 precision of the floral mechanism. For instance in the Orchidaceae, derived 



Fig. 1S36/S. 



from an Amaryllidaceous t^'pe with six stamens, Anastasia has three, 

 Cypripedium two, and Orchis only one — the anterior stamen. Ginger has also 

 only one, but it is the posterior. AU of these are highly specialised types : 

 their meiomery by abortion has followed parallel, but quite distinct lines. The 

 Valerianaceae show various degrees of abortion of the stamens ; but they also 

 have a reduced gynoecium. Here also three loculi are present in the ovary, but 

 only one bears a fertUe ovule. The same is the case in the Oak ; also in the 

 Coco-Nut. Here the three depressed scars on the shell indicate the three 

 carpels, but only the one that can be pierced by a pin matures its seed, and 

 forms a germ. 



A beautiful case of meiomery, invohing several steps, is seen in the 

 Scrophulariaceae. The flower is typically pentamerous, but it becomes 

 reduced to apparent tetramery. In the Mullein {Verbasciim) the formula 

 is S., Pc, Aj, G„. But in Scropkularia the posterior stamen is represented 



