ANIMALS INTRODUCED FOR SAKE OF UTILITY 257 



wander. Sporting animals on the other hand, are not en- 

 couraged to multiply to the same extent, and the very reason 

 of their introduction almost certainly insures that the breed- 

 ing stock will be periodically reduced within reasonable 

 limits. 



SUCCESS DEPENDS ON AN EVEN BALANCE 



All cases of utility importations, however, are not failures. 

 Where a balance is struck between natural food-supply and 

 numbers, an easy-going adaptation results. In 1911, forty 

 Reindeer were introduced into the Pribilof Islands off Alaska. 

 These thrived and by 1914 had increased in number to 150; 

 but soon the increase must cease for the supply of lichens is 

 limited, and more Reindeer might mean the loss of all. The 

 Honey Bee was imported into New Zealand in 1842 and 

 has flourished ; for the white clover previously introduced, 

 which had never seeded till the Bee was brought to fertilize 

 it, alone would have supplied abundance of food. So too with 

 the Humble Bee: for long the imported red clover bloomed 

 in New Zealand fields, but the flowers were sterile, and the 

 settlers had to bring their red clover seed from overseas. 

 Then the Humble Bee was introduced, and Humble Bee 

 and red clover struck a working balance the red clover, 

 fertilized by the visits of the Humble Bee, now ripens its 

 seeds, and the Humble Bee thrives on the red clover's 

 stores of honey. 



Of equal interest are the extraordinarily successful results 

 which have followed upon the introduction to California of 

 another fertilizer the Fig Insect (Blastophaga grossoruni), 

 a small Hymenopteronbelonging tothe family of the Chalcids. 

 For ten years a Californian orchard-owner grew figs with 

 uniform ill success. Doubting the quality of his stocks, he 

 then imported cuttings of Smyrna figs from their native home 

 in Asia Minor; but this too proved an utter failure, and for 

 fourteen more years his sixty-acre orchard never yielded 

 any financial return. It was known that wild figs containing 

 the Fig Insect were regularly placed in the Smyrna orchards. 

 Mr Roeding therefore imported in quantities from Smyrna 

 wild Capri figs containing Blastophaga alive, and at the 

 time of the blossoming of the figs, hung the insect-laden wild 



