INSECTS AND FLOWERS 239 



inner walls — access to which is gained through a small 

 orifice beset with leafy scales. The male and female 

 elements are borne by separate flowers ; while many 

 species of rig have two kinds of female flowers, namely, 

 some with long styles and developed stigmas, and some 

 with short styles and abortive stigmas. The latter are 

 called "gall-flowers" for a reason which will shortly 

 appear. The arrangement of the flowers varies in different 

 species ; but in the case of the common fig (Ficus carica) 

 of Southern Europe it is this : Some individuals produce 

 inflorescences containing only female flowers, while others 

 produce inflorescences with male flowers near the opening 

 and gall-flowers lower down. The former individuals are 

 known as Ficus, the latter as Caprificus. 



" We have to consider," writes Kerner in his Natural 

 History of Plants, " what may be the meaning of the gall- 

 flowers. As the name indicates, not fruits but galls are 

 produced from these modified female flowers, and this 

 happens in the following manner. There is a small wasp 

 belonging to the Chalcididce, . . . Blastophaga grosso?*um, 

 which lives upon the fig cultivated in the south of Europe. 

 This insect passes into the cavity of the inflorescence 

 through the orifice, and there sinks its ovipositor right 

 down the style-canal of a flower, and deposits an egg close 

 to the nucellus of the ovule. The white larva developed 

 from the egg increases rapidly in size and soon fills the 

 entire ovary, whilst the ovule perishes. The ovary has 

 now become a gall. When the wasps are mature they 

 forsake the galls. The wingless males are the first to 

 emerge, and they effect their escape through a hole which 

 they bite in the gall. The females remain a little longer 

 in their galls, and are there fertilised by the males. 

 Afterwards they come out also, but only stay a short 

 time within the cavity of the inflorescence, issuing from it 



