CO-OPERATION OF PLANTS. 215 



another variety which is productive of barren or worthless figs, 

 called the Caprificus variety. 



The inflorescence of the fig, most of you will know, is termed 

 a hypanthodium, being pear-shaped externally, but hollow in its 

 interior, where there are numerous flowers supported on a con- 

 cave receptacle. 



The flowers at the base of the inflorescence are usually pistil- 

 late, or female flowers, those at the top male or staminate. Now 

 the female flowers of the Caprificus or barren variety have short 

 styles, and they mature long before the male flowers, which are at 

 the summit of the inflorescence. The female flowers in the Ficus 

 or edible fig, have very long styles, each bent like a hook. Now 

 the insect, really a species of wasp, enters the inflorescence of the 

 Caprificus, or barren fig, proceeds to the female flowers, sinks its 

 ovi-depositor down to the short style, and deposits the egg inside 

 the ovary. The iarva from the egg increases in size, and fills 

 the whole of the ovary, which thus becomes abortive, producing 

 what is termed a gall-flower, so that in the Caprificus, or barren 

 fig, all the ovaries of the female flowers have been converted into 

 gall-flowers, hence its barrenness. The insects inside the galls, 

 when hatched, eat their way out from the gall, creep to the top of 

 the inflorescence, and on emerging have to forcibly brush through 

 the male flowers, which are now ripe and discharging their pollen ; 

 thus, the wasp on emerging is covered with pollen. These insects, 

 seeking a place to deposit their ova, arrive at the inflorescence of 

 the fertile fig, into which they descend and proceed to the pistil- 

 late flowers. These pistillate flowers have different styles to those 

 of the barren fig, and the wasp is unable, in nearly all cases, to 

 deposit the egg in these ovaries, on account of the great length 

 of the style and its hooked nature ; therefore the wasp, in its 

 fruitless endeavours to enter, passes from flower to flower, dabbing 

 the pollen brought from the other fig on the stigmas of these 

 flowers, so causing the cross-fertilisation which is so imperative 

 for the formation of good individuals. The labour of the insect is 

 rewarded probably, after visiting some hundreds of flowers, by 

 finding a flower suitable to lay its eggs in. The plant gains by 

 being cross-fertilized ; the insect gains in return shelter for its 

 young. The two therefore co-operate. In order that this action 



