THEIR RELATION TO PLANTS 33 



At the same time that the Smyrna fig which produces 

 the edible commercial fruit is in bloom, there is also 

 another crop developing on the caprifigs, and these are 

 known as "mammoni. " The Blastophaga issuing from 

 the "profichi" on the same tree, naturally enter these 

 fruits which are of the same character as the preceding 

 crops, and are able to continue their kind, coming to 

 maturity when the third crop is ready for their reception. 

 This third crop represents the "mammae" or over- 

 wintering form, from which the "profichi" of the fol- 

 lowing season are again entered by the Blastophaga. 



Here we have an extremely complicated relation- 

 ship which, reduced to its simplest terms, means that 

 in order to produce the commercial Smyrna fig there 

 must be suitable caprifigs producing "profichi" infested 

 by Blastophaga, at a period corresponding to the develop- 

 ment of the female flower capsule. And as the insects 

 are very small and very frail, the caprifigs must be 

 either well distributed among the Smyrna trees, or the 

 infested "profichi" must be gathered and distributed 

 among the trees to be pollenized. 



The accounts, published by Dr. L. O. Howard in the 

 Bulletins and Reports of the U. S. Department of 

 Agriculture, make interesting reading and show how, 

 after many trials and much painstaking investigation, 

 the Blastophaga and the necessary caprifigs were finally 

 introduced into the fig-growing districts of California, 

 and how a new industry, absolutely depending for its 

 continuance upon a minute hymenopterous insect, was 

 finally established upon a firm and scientific basis. 



How many cases of this kind exist among plants 

 having no present economic value it would be difficult 

 to estimate, and how so complicated a relationship ever 

 became established is not yet explainable even by a 

 theory. 

 3 



