162 DISPERSION OF POLLEN BY ANIMALS. 



stigmas not being adapted to the reception of pollen they do not promote the 

 growth of pollen-tubes, and no fertile seeds are produced. On the other hand, 

 pollen-tubes develop on the stigmas of the long-styied flowers, and the latter pro- 

 duce fertile seeds; but the long-style prevents the proper placing of the wasps' eggs, 

 and consequently galls are never or very seldom produced in connection with these 

 flowers. 



It would take too long to discuss all the numerous diversities which have been 

 observed in other species of Fig, even if they were known with sufficient accuracy 

 to admit of a general survey. We will only mention that there are approximately 

 600 species of Ficus, which are distributed over the tropical and sub-tropical regions 

 of both the Old and the New Worlds, and that up to the present time nearly 50 

 species of small wasps of the genera Blastophaga, Crossogaster, Sycoi^haga, and 

 Tetrapus have been identified as efiecting the transference of pollen from one 

 inflorescence to another in the various species of Fig. Thus, for instance, Blasto- 

 pliaga Brasiliensis has been identified in the inflorescences of seven difierent kinds 

 of Fig-tree. For the most part each species of Fig has its own particular wasp; 

 only in extremely rare instances have two dififerent species of wasp been found in 

 the inflorescences of one and the same species of Fig. 



In Southern Italy and other parts of Southern Europe where the Fig has been 

 extensively cultivated for ages, the majority of the trees planted are Ficus- 

 individuals, i.e. such as have female flowers only in their inflorescences, these 

 yielding the best and juiciest figs. Fig-plants of the form known as Caprificus, 

 which, besides male flowers, contain only gall-flowers in their inflorescences, are not 

 cultivated, because most of their figs dry up and fall off" prematurely. A few 

 specimens of Gaprißcus are reared here and there in order that their inflorescences 

 may be artificially transferred to the branches of the Ficus-trees. The process of 

 transference is called caprification, and the growers believe that the figs of Ficus 

 are improved by the wasps which come out of the C'apr^/ic^^s-inflorescences and 

 enter those of the Ficus. But this opinion, though very wide-spread amongst 

 cultivators and peasants, is not correct. The figs of Ficus do not require the 

 intervention of wasps to become sweet and juicy. As a matter of fact, Ficus- 

 inflorescences which have been entirely unvisited by wasps and have developed no 

 fertile seeds in their little fruits, ripen into excellent eating figs, and innumerable 

 quantities of the figs sold come from trees and from districts where no process of 

 caprification is employed. It seems, therefore, that the use of caprification must be 

 traditional and have originated at a time when growers were not only concerned 

 with the production of good fruit but of fertile seeds also with a view to the 

 multiplication of the plants. At the present day Fig-trees are no longer raised 

 from seed but from cuttings, and caprification is consequently superfluous. Never- 

 theless the country people persevere with the old custom in spite of their ignorance 

 of its real significance. 



Flowers and floral envelopes are comparatively seldom called upon to act merely 

 as a shelter for the night, or as a temporary refuge. Most bees and wasps have 



