FIG-INSECTS 549 



more than an old custom destitute of practical utility. On the 

 other hand, Riley states l " that the perfect Smyrna fig, the most 

 esteemed of the edible species, can be produced only by the 

 intervention of the Blastophaga psenes [grossorum]." 



Although the questions connected with the effect the Blasto- 

 phaga is supposed to produce on the fruit are of a botanical 

 rather than a entomological nature, we may briefly say that two 

 views have been held : (1) that, as in the fruit of the cultivated 

 fig, only female flowers are produced, the Blastophaga is necessary 

 for their fertilisation and the subsequent development of the 

 fruit; (2) that the Insects stimulate the fig by biting parts 

 thereof or by burrowing in it, and so give rise to the processes 

 that have as their result the edible fruit. There seems to be 

 little doubt that the Insect agency is necessary to the fertilisa- 

 tion of some species of, figs. Cunningham, who has recently 

 carried out an elaborate investigation as to the fertilisation 

 of Ficus roxburghii, 2 concludes that in this fig, and probably 

 also in other kinds, the perfect development is dependent on 

 the access of the fig-Insects to the interior of the receptacular 

 cavity. Should access fail to occur, both male and female 

 flowers abort, without the formation of pollen grains by the 

 former or seeds by the latter. The access of the Blastopliaga is 

 thus as necessary for the perfect evolution of the normal male 

 and female flowers as it is for that of the modified ? or gall- 

 flowers, with their contained ova and Insect-embryos. Whether 

 the successful fertilisation of the flowers is really essential to the 

 production of the edible fig is not a question for our discussion. 



Fig- Insects are apparently more numerous in South America 

 than they are in any other part of the world ; and Fritz-Miiller 

 has discovered 3 a number of species there of a very extraordinary 

 character, several of them possessing two forms of the male, one 

 winged like the female, the other wingless and so different in 

 character that they were considered to belong to a different genus. 

 The wingless male of a species found in Madagascar, Kradibia 

 cowani, has the peculiarity of possessing only four legs, the middle 

 pair being represented merely by minute two-jointed rudiments. 

 Some of these Insects live in galls on the figs. The fig-Insects 



1 P. Uol. Soc. Washington, vii. 1892, p. 99. 



- Ann. Botan. Garden, Calcutta, i. 1889, Appendix L. 



3 P. ent. Soc. London, 1886, p. x. 



