28 



MISSOURI BOTANICAL GARDEN. 



TABLE A. 



No 



1 



2 



3 

 4 



5 



No. 



1 



Seed 



flowers 



125 



112 



79 



39 



45 



Seed 

 flowers 



148 

 114 



Gall 

 flowers 



Per cent. 



female flowers 



with galls. 





Staminate 

 flowers. 



Per cent, stanv 



inate among 



all flowers. 



103 

 117 

 104 

 101 



87 



45 

 51 

 57 

 72 

 66 



21 

 14 



13 



8.4 



FICUS AUREA. 



TABLE B. 



Gall 

 flowers. 



Per cent. 



female flowers 

 with galls. 



I 



Staminate 

 flowers. 



Per cent, stam- 



inate among 

 all flowers. 



230 

 247 



66 

 08 



54 

 73 



12.5 

 17 



FICUS POPULNEA. 



V 



In many species of Ficus there are two types of pistillate 

 flowers, one producing seeds, the so-called seed flowers, and 

 the other present only to receive the BlastopJiaga eggs, one in 

 each flower, producing the Blastophaga galls, the so-called 

 gall flowers. These gall flowers require the stimulus of the 

 egg to cause them to develop further. Otherwise they de- 

 generate, as they are incapable of producing seeds. Careful 

 study of the flowers shows that this distinction does not exist 

 in the species under consideration. It is indeed a fact that two 

 extremes of the pistillate flowers may be distinguished — those 

 with long and those with short styles (plate 8, figs. 1-3, F. 

 aurca; 8-9, F. popuhica). This is correlated with the length 

 of the flower pedicel so that all the stigmas occupy the same 

 level. The difference in length of the pedicels seems to be 

 an arrangement permitting the flowers to be present in two 

 layers instead of in merely one. There are many intergrada- 



tions, however, between the two extremes (plate 8, fig. 2). 



