QUEKETT MICROSCOPICAL CLUB. 43 



male figs and three weeks for the female. The first male ciop 

 ripens in November and December, when the second male and 

 female crops are fit for the insect to enter. The second male 

 crop ripens in April and May, when the first male and female 

 crops are ready for the insect to enter. The insect in this case 

 is a species of Ewpristis. If insects do not enter the figs at 

 the proper time they dry up and fall ofi the tree. When the 

 figs are ready for the insect the flowers are all nearly at the 

 same level; the male flowers are whitish and the female and 

 gall flowers pink. The male fig contains male flowers below 

 and gall flowers aromid the " eye," and one to three insects 

 enter each fig. The insect forces its v/ay through the bracts 

 which close the aperture of the fig, and begins to deposit an egg 

 within the nucellus just outside the embryo sac of each gall 

 flower. This causes the galls to form without injury to the fig, 

 and also causes the male flowers to develop. The penetration 

 is made through the tissue at the top of the ovary, and not by 

 way of the style in this species, and this being tougher in the 

 female flowers the insect cannot penetrate it, and dies, having, 

 however, fertilised the female flowers by the pollen it has carried 

 in. Some days after the entry of the insect the figs become 

 filled with fluid, and the flowers elongate irregularly, so that 

 they are not overcrowded. When nearly ripe the fluid is 

 absorbed, and the male flowers develop and begin to shed 

 their pollen. Then the Eupristes begin to emerge from the galls, 

 the males, which have strong jaws, emerging first by cutting a 

 hole in the gall. The males then gnaw a hole in each gall con- 

 taining a female, and fertilise them before they come out. When 

 all the females are free the males cut a- tunnel through the eye 

 of the fig, and in so doing cut away all the stamens, and all the 

 insects are dusted with pollen. The males are wingless and soon 

 die ; the females fly away to find a fig fit for their reception, 

 and seem unable to distinguish between male figs in which 

 they can oviposit and female ones in which they cannot. Dr. 

 Cunningham found that by the time the insect had got through 

 the bracts into the fig most of the pollen was brushed ofi ; he 

 never found more than two or three grains inside a fig. From 

 this he concluded that the number of pollen grains was in- 

 sufiicient to fertilise the thousands of ovaries in a fig, and that 

 the insect's attempts to oviposit must be a sufficient stimulus 



