REVIEW. 663 



by insects both kinds of fruit develop only up fco a certain point and then 

 wither without producing either pollen or seeds ; but if visited they com- 

 mence to swell at once and come to full maturity in due course. The whole 

 circuit of operations, as described by Colonel Cunningham, is briefly this. 

 The female insect enters a male flower and deposits her eggs in the modified 

 female flowers. The larvae develop inside the ovarian receptacle and the 

 males emerge first. It is not stated by the author whether the insect is 

 Hymenopterous, Dipterous or Lepidopterous, but he says that there are three 

 species, found in Calcutta, Sikkim and Cherat respectively. No doubt they all 

 belong to the family of Hymenoptera mentioned above. The male has no wings, 

 but very powerful jaws, by means of which it cuts a way through the dense plug 

 of stiff , glutinous bracts that practically blocks up the orifice which is structurally 

 present in all figs. Having thus opened a way to liberty for the winged but 

 feeble females, they perish. The females follow, after wandering among the 

 pollen-covered anthers of the male flowers, and so many as are not snapped up 

 by the eager enemies that lie in wait for them at the gate fly away in quest of 

 other fig trees bearing fruit, to which they may commit their eggs. And here 

 is a wonder. Before attempting to enter any fruit they examine it carefully 

 and ascertain unerringly whether it has arrived at a proper stage of 

 development for their purpose, but they fail to distinguish between male 

 and female fruits. Consequently many try to enter the latter. The 

 plug of bracts in the female fruit is particularly dense and there are no gallant 

 males now to open a way, so the majority stick and perish in the passage, but 

 a few struggle through to find that they have made a mistake. They wander 

 about, plunging their ovipositors vainly into the thick and resistent ovaries of the 

 unmodified flowers and die without issue. " But though such attempts," says 

 the author, "are entirely futile in so far as the end to which they are directed 

 is concerned, they are of immense importance in the economy of the fruit 

 which is attacked;" for the stimulus supplied by the deluded insects is followed 

 by general hypertrophy and the development of fertile seeds. It will of 

 course be assumed that this is the result of the pollen brought from the 

 male fruits getting brushed off on the stigmata. Not so. Colonel Cunningham 

 has satisfied himself that the obstructions through which the insect has to pass 

 before it penetrates the female fruit leave no appreciable amount of pollen 

 adhering to it, and further that the small number of insects that manage to get in 

 could not possibly pollinate the number of flowers that are affected. In one case 

 in which there was no evidence of more than one insect having got into a fruit, 

 11,000 mature seeds were counted in it. This part of the argument, the whole of 

 it indeed, is rather diffuse and indirect, but the author plainly arrives at the con- 

 clusion that the general hypertrophy of the reproductive parts induced by the 

 stimulus which the insects apply leads to the parthenogenetic production of seeds. 

 Colonel Cunningham seems scarcely to realise the startling and revolutionary 

 character of this proposition and he makes no attempt to face the problems into 

 which it plunges us. If it is true, let us consider some of the corollaries. 



