476 DR. M. T. MASTERS ON THE SUPERPOSED 



S5 



P5 



St 5 



X 5 



01 



Where 



described j or it may be as follows 



S 



P 



St 



Phlebocaly 



may be the representative of an antipetalous whorl of stamens. 



Natsiatum ... „ __ „_ 



So 

 P5 



X S 



St 5 



there being in this genus a row of staminodes antipetalous and 

 outside the fertile stamens. Baillon, indeed, describes the stami- 

 nodes as " interposed " between the fertile stamens, thus 



S5 



P5 



St 5 x 5. 



But id the flowers examined by myself the sterile stamens ap- 



peared 



It is possible 



however, that the history of development may bear out Baillon's 



interpretation. 



In the preceding examples (if the last one be excepted) the 

 stamens, staminodes, and glands of the disk are isomerous with 

 the petals in their respective whorls ; but in other Olacacese we 

 get in the same whorl a larger number of stamens, or of stamens 

 mingled with staminodes than of petals. The formula for Ximenia, 

 Ctenolophon, and Ptychopetalum, for instance, is 



S 



P 

 St St, 



there being usually ten stamens in a single whorl, five being anti- 

 sepalous and five antipetalous. In Ctenolophon, as the five anti- 



