206 OUR INSECT FRIENDS AND FOES 



numbers near the orifice, whilst in others there 

 are very few indeed, it even happens some- 

 times that there is an entire absence of male 

 flowers in one inflorescence or another. In 

 many species some individuals only produce 

 inflorescences containing female flowers, and 

 other individuals inflorescences with male 

 flowers near the orifice and with female flowers 

 lower down. But the most remarkable circum- 

 stance of all is that in the inflorescences of 

 many species, all or most of the female flowers 

 below the male ones are transformed into 

 gall-flowers. This is the case, for instance, in 

 the common Fig-tree (Ficus Carica) cultivated 

 in Southern Europe, a species which includes 

 two kinds of individuals, viz. those whose 

 inflorescences contain female flowers only, and 

 those whose inflorescences contain male flowers 

 near the opening, and gall-flowers lower down. 

 The former individuals are known by the name 

 of Ficus, the latter by the name of Caprificus. 

 We have now to consider what may be the 

 meaning of the gall-flowers. As the name indi- 

 cates, 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 Chalcididae, a family of 

 Hymenoptera, already referred to as Blastophaga 

 grossorum, 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 





