8 



The Journal of Heredity 



lose her wings. The presence of these 

 protruding from the "eye" is a sure sign 

 that the wasps have entered the fig. 

 The presence of a minute hardened 

 drop of sap also denotes the entry of 

 the wasps. When they have reached 

 the cavity of the fig they proceed to lay 

 an egg in each flower, after which they 

 die. 



The number of insects which enter 

 each fig varies between two and thirty- 

 six. They are more plentiful in autumn 

 than at any other season. At that time 

 the number of eggs laid in each fruit 

 is at least 1,000. This is the number 

 actually counted, but there must have 

 been many more which esca]jed observa- 

 tion in the disintegration of the flowers. 



In summer the insects enter the figs 

 when the latter are 15 to 20 days old. 



CH.\N'GES IN THE FIG 



As soon as the eggs are laid, the fig 

 commences to secrete a watery fluid 

 which eventually fills the cavity to 

 about one-fourth of its capacity. 



Before the time arrives for the young 

 insects to emerge from their cells, the 

 fluid is again absorbed and the interior 

 of the fig returns to its original condi- 

 tion. The ]jeriod which elapses between 

 the laying of the eggs and the emergence 

 of the young insects is about a month. 

 The dcvelo]jment of the wasjjs thus 

 coincides with the growth of the figs, 

 so that when the females leave the 

 fruits of one crop, those of the following 

 crop are ready to receive them. This 

 may be represented apj^roximately as 

 follows : 



Crop No. 1 

 Commences growth April I 

 Insects enter figs Aj^ril 15 

 Young insects emerge May 1.^ 



Crop No. 2 

 May 1, commences growth 

 May 15, insects enter 

 June 15, young insects emerge. 



As we huve already explained, in 

 autumn there is a continuous prodticticjn 

 of fruits so that whenever the wasi:)s 

 come out of the mature figs they find 

 others of a suital)le age in which to lay 

 their eggs. In winter the growth oi" 



both figs and insects is slower than in 

 .summer. 



We have not been able to find seeds 

 in any of the figs. It therefore appears 

 that the only raison d'etre of the figs 

 is to provide food and shelter for the 

 wasps. 



In fact, experiments tend to prove 

 that, in the absence of the insects, the 

 figs are not able to continue their 

 growth beyond the initial stages. 



We have surrounded the young fruits 

 with muslin bags and thus ]3revented 

 the access of the Sycojjhaga to the figs, 

 and in no case has the usual secretion 

 of liquid taken place inside, but, on the 

 other hand, after the lapse of a few days 

 the figs have shrivelled and fallen. 

 The presence of the wasp, therefore, 

 appears to be an essential condition 

 for the development of the fig itself. 

 We naturally suppose that the use of 

 the fig to the tree in its i)rimitive state 

 was the i^roduction of seed for the 

 propagation of the species. 



SEEDS SOME-TIMES PRODUCED 



Sickenberger in his "Contributions a 

 la flore de I'Egypte" states that the 

 tree produces perfect seeds in Nubia, 

 Abyssinia and Yemen. Inquiries made 

 in the first-nained country have not 

 enabled us to confirm that statement. 

 As stated by Muschler, Dr. Schwein- 

 furth saw many seedling trees growing 

 spontaneously in the Yemen, so that 

 the tree evidently still retains the 

 power of i)roducing good seed there. 

 The (lucstion, therefore, arises: Is the 

 Sycoph'.iga not found in that country 

 and have the figs been ada]jted to the 

 needs of the insects since the tree came 

 to Egypt? We may also ask whether 

 in that country the seed-l)earing flowers 

 exist side by side with cAhers in which 

 the insect breeds, as is the case in the 

 ca])rifig. 



It has been stated I hat I lie sycamore 

 insect is that which elTecls caprification 

 of the common fig in Malta, but this 

 statement docs not a])pear to be ba.sed 

 upon fact. In this connection it is inter- 

 esting to comi)are the common cai)rifig 

 insect Blastopha^a firossorum with the 

 S\-camore was]) Sycopha^a crassipes. 



