ETTRODTJCTION
DR, CUNNIISTGHAM'S MEMOIR.
IT has been assumed in the following paper that the nature and arrangement of the
flowers in the receptacles of dioecious species of figs are familiar to the reader ; but in case
they may not be so, it may be well to give a brief description of them. The receptacles
consist of hollow, flask-shaped or spheroidal bodies, the cavities of which are bnunded by
solid ^7•a^s save at their apparent apices, where these are replaced by masses of the appressed
and interlocking bracts of the so-called ostioles. In F. Boxhirghii and many other species
tlie arrangement of these bracts is such as practically to convert the interior oi the receptacle
into a closed cavity. In this species two distinct kinds of receptacles are to be met with,
each kind being confined to particular trees. In one of these two forms of flowers are
present, viz. (a) true male flowers situated in the neighbourhood of the ostiole and capable
of producing pollen, and (i) modified female or gall-flowers, which never produce seed, but
within the ovaries of which in veiy many cases the ova of certain species of insects are
deposited and undergo evolution. In the second kind of recoptacles no male flowers are
present, and the floral sui-face of the cavity is occupied by true female flowers, which never
contain the ova or embryos of insects, but which are capable of producing fertile seeds.
The perfect evolution of both male and true female flowers in Ficus RoxlurgUi, and
probably in other species also, is dependent on the access of the fig-insects to interior of the
receptacular cavity. Should access fail to occur, both forms of flowers abort without the
formation of pollen-grains in the one case or seeds in the other, and the access of the
insects is thus as necessary for the perfect evolution of the normal male and female flowers
as it is for that of the modified female or gall-flowers with their contained ova and iosectembryos.