14 ON THE FiiRTILIZATiaii
representing the crops maturing in the early part of the cold weather. These statements
must, however, be taken very generally, as great differences in regard to the numbers of
receptacles developed at different periods appear to occur from year to year, and occasional
buds may bccome developed at almost any time.
Much more definite data are available in regard to the duration of any crop which
comes to matui-ity. The entire period from the first appearaiice of the buds of a crop of
gall-receptacles to the escape of the fig-insects ranges between four and five months
varying somewhat according to the character of the season; two months intervenino- between
their first appearance and the attainment of the stage of development i-enderino- tliem
suitable for the access of the insects, and two to three months from that time u°til full
maturation takes place. Maturation proper is, however, dependent on the access of insects
and should this fail to take place, the receptacles dry and fall about a mouth after they were
ready to be entered. ^
It is very difficult to determine the question of the number of annual crops of receptacles
which mature on the female trees, as only a small number ever do mature even after they
have been effectively visited by the fig-insects, due to the fact that in a large majority
of cases they are attacked by the larva of some species of Lepidopterous insect, which, after
spending the earlier portion of its existence in devouring the flowers, ultimately escapes
by perforating the ostiole, and thereby causes escape of the receptacular fluid and
consequent drying up and fall of the figs. In the case of the female tree in the Botanic
Garden, from which alone normal ripe receptacles have been as yet obtained there is
only one site where they as a rule occur. This is at the very base of one of the stems
where the fertile twigs are actually on the ground and the rcceptacIcs are crowded
together among the grass and weeds, which must apparently serve to protect them from
the visits of the winged parents of the grubs. Here two, if not more, crops certainly
matm-e in the course of the year—one in the end of February aud March, the other in
the latter half of May and beginning of June. The duration of any crop which successfully
matures appears to be almost the same ai in the case of the male receptacles, a period
of from one to two mouths intervening between eruption of the buds and attaiomeut of
the stage for the access of insects, aud two to three months between that and the occun-ence
of full maturation. For example, on the 10th of Mai-ch 1888, the fertile twigs on the
tree in the Botanic Garden were beginning to be covered with buds, some' of them
having already attained the size of hazel-nuts; on the 26th March some receptacles were
ready for insects; on the Gth April some had already been entered; aud on the 29 th
May ripe receptacles were present. The previous crop has a somewhat longer dm-ation
no doubt due to the lower temperatui-c to which it is exposed, and receptacles which
are entered by insects in the end of November do not ripen until the end of February.
The eruption of now crops of receptacles sometimes occurs along with that of
new leaves, but there is no nccessary association of the two events. There are two periods
of defoHation—the first and most complete fall taking place in the lattei- part of the cold
weather in February, and a second one, which varies in degree with the nature of the season
occuiTing during the second half of the hot weather; the fall increasing in amount with the
heat and diyness of the season. Dui-ing the past season an eruption of a new crop of
receptacular buds occurred simultaneously with the spring change of leaf on the female tree
in the Botanic Garden, while none occm-red at the same time on any of the male ones, in
two of which at all events the previous crop of receptacles dated from the middle of the cold
weather, when no change of leaf occiu-s,
OF FICUS EOXBUEGHir. 15
The rccciitacles of Ficus Uoxhxirgliii.
In passing on to a description of the receptacles no mere general data are sufficient, and
it is necessary to give details in regard to tiie condition of both female and male or gallreceptacles
at different stages of development, and in relation to the fact of the fig-insects
gaining access to them or failing to do so. We have thus to consider the features
presented by each class of receptacles under the following headings:—
1. Characters at the stage when they arc ready for the access of insects.
2. Characters of receptacles after insects have attained access, but before maturation.
3. Characters of mature receptacles to which insects have gained access.
4. Characters of mature receptacles to which insects have not gained access. Such
receptacles are divisible into two varieties—
(a) One in which no appreciable development has occurred after the flowers
have reached the condition which they normally present at the time
for access of insects.
(5) One in which a certain amount of evolution of the male flowers or of
some of the true female flowers has occurred beyond that condition.
I.—JIALE OR GALL-RECEPTACLES.
A.~Charadcrs at Hit stage when ihcy are ready for the access of insects.
The following are the measurements obtained from a receptacle of average dimensions :—
External diameter 2"'0
Thiols ness of wall o"-25
Thickness of plug of ostiolar bracts 0"'30
Diameter of area in centre of ostiolar aspect of cavity occupied by empty
bracts 0"'49
Breadth of surrounding zone of male flowers O'-Sl
Breadth of peripheral zone of gall-floweis on ostiolar aspect of receptacular
cavity 0''-2i
Depth of gall-flower stratum 0" OB
The ostiole is at this time closed by a firm, solid plug of closely appressed ostiolar bracts,
and the central area of the ostiolar aspect of the cavity is thickly clothed with others (Plate
IV, figs. 21, 22). Around this bracteal area a nan-ow zone of true male flowers is situated,
aud external to it the continuous stratum of gall-flowers which lines all the rest of the
receptacle commences (Plate IV, fig. 22). The area of bracts and male flowers forms a
central concave boss on the ostiolar aspect of the cavity, the concavity mainly being due
to the fact that the male flowers and their bracts stand erect, while the empty bracts are
situated on an inclined basis, and become more and more oblique as they pass onwards along
the course of the ostiolar channel; in the central portion of which they are arranged
horizontally (Plate IV, figs. 21, 23, 23). Li passing from without inwards along the course
of the ostiolum, we first meet with bracts directed upwards and inwards in varying degrees
of obliquity, next with horizontal ones, and then with a series which are directed downwards
and inwards towards the cavity; the inclination becoming steeper and steeper