SOME KEMARKABLE ADAPTATIONS OF PLANTS TO INSECTS. 103 



that the bh*ds to get at the pitchers must brush against them, and thus 

 convey the pollen from one plant to another. 



" A second species of Marcgravia that I found in the woods around 

 Santo Domingo has the pitchers placed close to the pedicels of the 

 flowers, so that the birds must approach them from above ; and in this 

 species the flowers are turned upwards and the pollen is brushed off by 

 the breasts of the birds." 



In examining " pitchers " in specimens in the Museum of Natural 

 History I found they consist entirely of hollow axes with an abortive bud 

 at the apex. 



The Gall-flower of the "Wild" Fig, or " Caprificus." 



Another instance of a perpetuated adaptation is seen in the so-called 

 gall-flowers of the "wild" fig, or the Caprificus of the ancients. 



This fig never produces edible fruit, as every ovary is the home of a 

 grub of an insect known as Blastophaga grossorum. 



The ordinary pistil of the edible fig is somewhat fusiform in shape, 

 with two spreading stigmas ; but in the gall-flower the ovary is globular 

 and the stigmas are aborted. The summit of the ovary has a depression 

 easily penetrated by the ovipositor of the fig insect, but the insect is 

 unable to penetrate that of the edible fig. The peculiar form of the ovary 

 of the gall-flower is thus now prepared in advance in adaptation for the 

 reception of the egg. 



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