19£1] The Age of Insects 49 



bees is not less absolute. Australia has no native bumble-bee, and 

 red clover was unknown there until the colonists began to cultivate it. 

 There was no difficulty in making crops of forage; but it would not 

 seed. Importing seed annually was expensive, and, naturally, the 

 Australians were anxious to raise their own. This led to a study of 

 the reasons for the failure, in the course of which the dependence of the 

 plant upon bumble-bees was established. The remedy was obvious, 

 and now European bumble-bees disport themselves among the Aus- 

 tralian red clover, seed is plentiful, and interference with bumble-bees 

 is a crime^ — as it should be rated everywhere. 



"There are many others among the Hynienoptera that are useful 

 in the work of pollination because of their habit of feeding among the 

 flowers, even if not on them; but all this is based on the same visits 

 which the flower encourages and of which it takes advantage; but no 

 account of this sort of relationship could be considered even passably 

 complete without some reference to the complicated relationship 

 existing between the Smyrna fig and the minute little Blastophaga, a 

 species whose life relations have been beautifully worked out. 



"The Smyrna fig of commerce depends for its edible quality upon 

 the ripened seeds that it contains. The fig is not really a true fruit as 

 that term is generally defined, but is a thick fleshy envelope within 

 which the flowers are contained. In the Smyrna fig these flowers are 

 all female and no pollen is produced anywhere on the tree. Left to 

 themselves, such trees could never produce ripe fruit, and that was the 

 condition of the Smyrna fig orchards in California, prior to 1900. In 

 the Mediterrenean countries, whence our commercial supply is de- 

 rived, there are found beside the cultivated also several varieties of 

 wild or caprifigs, which produce three crops of fruit during the season. 

 These fruits contain male flowers, producing an abundance of pollen; 

 but this pollen is never naturally discharged from the envelope con- 

 taining the florets. 



"Yet it was recognized by the fig-growers in the Orient that to ob- 

 tain fruit of the commercial edible varieties, it was necessary to bring 

 to them when in bloom, branches containing fruit of the caprifig, which 

 were usually hung up in the tree which it was intended to fructify. 

 This work of pollination is accomplished by the Blastophaga already 

 referred to, although, far from benefiting itself in the process, the in- 

 sect dies without even being able to continue its kind. 



"In the caprifigs the female flowers are replaced by little gall-like 

 swellings in which the larvae of the Blastophaga develop. One gene 



