Tin- l-l^KTILISATION OV THE FIG. 



llv PROFKSSOK 1-. c A\ EKS. D.Sc. F.L.S. 



Nf rcH has Ixcn written, from the time of the earliest 

 Greek naturalists to the present day. concerning the 

 fertilisation of the fig. but it would appear from some 

 recent researches that the problem is by no means 

 cleared up yet. and that the process is one of great 

 complexity, involving one of the most astonishing 

 examples of symbiosis, or mutual relationship be- 

 tween organisms, that has ever been disclosed. 



The genus Ficiis is an extensive group belonging 

 to the familv Moraceae. which includes also the 

 mulberry, and which is related closel}' to the nettle 

 and elm families. Besides the various kinds of figs. 

 Ficiis comprises among its six hundred species, 

 which are chiefly indigenous to the East Indies and 

 Polynesia, such well-known plants as the indiarubber 

 tree, the banyan, and the peepul. 



The edible fig of commerce i Ficiis carica ) appears 

 to be native in Asia Minor and Syria, but now grows 

 " wild " in most of the countries around the Medi- 

 terranean. Doubtless owing to the ease with which 

 its nutritious fruit can be preserved, the fig was 

 probably one of the earliest plants to be cultivated. 

 According to Herodotus, the fig was unknown to the 

 Persians in the time of the first Cyrus, but it must 

 have spread in remote ages over all the countries 

 around the Aegean and the Levant. Apparently the 

 Greeks received the fig from Caria, whence the 

 specific name, but they improved the fruit so much 

 by cultivation that Greek figs became celebrated 

 throughout the East. From Greece, at some pre- 

 historic time, it was taken to Italy, where numerous 

 varieties, mentioned by Pliny, arose under cultivation. 

 The fig is now grown in all the Mediterranean 

 countries, but the greater portion of our supply comes 

 from Asia Minor, Spain, and the south of France. 

 It was introduced into England from Italy bv 

 Cardinal Pole in the sixteenth century, and is grown 

 for its fresh fruit in all the milder parts of Europe 

 and the United States, though farther north it 

 requires protection in winter and a south wall for 

 its successful cultivation out-of-doors. 



In the fig. as in other species of Fictis, the flowers 

 are produced inside a hollow pear-shaped receptacle 

 opening bv a narrow pore at the top. Just below the 

 mouth, in most species, are the male flowers, while 

 the rest of the cavity is lined by the closely packed 

 female flowers. The individual flowers are small and 

 of simple structure, the male having only one or two 

 stamens and the female a small ovary with a slender 

 style at its apex. 



It has been known for some time that the flowers 

 of Ficiis are fertilised by means of small wasps 

 called Blastophaga and Sycof)hiJi<a. The female 

 wasp enters a fig and lays its eggs in the ovaries of 

 the female flowers ; this occurs at an early stage, 



\\ hen the stamens of the male flowers have not yet 

 opened. The male wasps arising from these eggs 

 fertilise the females, and as these emerge from the 

 opening of the receptacle they are dusted with pollen 

 from the male flowers, and carry the pollen to other 

 inflorescences. 



According to more recent investigations, however, 

 the story of the relation between the wasp and the 

 fig-tree is longer and more involved than this simple 

 statement would impl\\ Tschirch* has recently 

 published a memoir on the wild and cultivated figs 

 of Ital\", based chieflv upon extensive observations 

 made by the Italian botanist Ravasini. .\pparentl\- 

 there are three forms of Ficiis carica — (1) the wild 

 fig itself, (2) the male plant or Caprificus (Ficiis 

 carica a caprificus), and (3) the female fig {Ficiis 

 carica fi domestica). The two cultivated forms, 

 male and female, are varieties which have arisen from 

 the original wild fig : the caprificus form, being 

 f unctionallv male, of course produces no seeds, while 

 the seeds produced bv the domestica form give rise 

 to seedlings which revert to the wild fig. 



The wild fig produces three generations or crops 

 of inflorescences. (1) The '" profichi," appearing in 

 Februarv or March and ripening in June, contain 

 only male flowers and short-styled female flowers 

 which produce no seeds, and are not edible. (2) The 

 " fichi," appearing at the end of May on the 

 lower parts of the branches and ripening in 'Septem- 

 ber, contain long-styled fertile female flowers, and 

 are edible. (3) The " mamme," appearing in 

 September on the young shoots and ripening in 

 March or April of the following year, contain only 

 the short-stvled flowers producing no seeds, and are 

 not edible. The " profichi '" constitute the male 

 generation ; they remain hard and contain little or 

 no sugar, and are usually filled with the wasps — 

 Bhistophaga grossoruin. The " fichi " form the 

 female generation, producing seeds and becoming 

 fleshv and sweet. The " mamme," which remain 

 quite small, serve only to harbour the wasps during 

 the winter ; they wither and fall off in spring when 

 the insects have escaped. 



The female w asp enters the " mamme " in autumn 

 and deposits her eggs in the short-styled flowers, 

 stinuilating these to grow into "gall-flowers," con- 

 taining a larva instead of a seed. Tschirch states 

 that these flowers contain an undifferentiated mass 

 of tissue instead of a normal ovule or " young seed," 

 but according to other writers an ovule is present 

 though it does not ripen into a normal seed ; in any 

 case, these flowers are specially adapted for the 

 nursing of the wasp larvae, since the female wasp is 

 able, owing to the shortness of the style surmounting 

 the ovary, to penetrate the latter with her ovipositor 



Bcrichtc d. thiitsch. hot. Gcs.. XXIX. 



