INTRODUCTION 



IX 



In the majority of the -all flowers an insect deposits an egg, and many of then, 

 contain a pupa, which is easily seen throu h the oats of the false ache* The ima , 

 escapes into the cavity of the receptacle by cutting its way throu h the* coat ami th. 

 fully developed winged insects are often to he found in considerable DUmbc in the cavitv 



of the fig, the opening by which each escaped from the ovar in which it was devel- 

 oped being clearly visible. In many species the ] rfeet insects escape from the cavity i f 

 the receptacle into the open air by a passage perforated by the males through th >< ah ^ 



that close the mouth of the latter. The egg of the insect must in man eas. s bo d< ]>ositc<l 

 in the ovary of the gall flower at a very earl period; for about the time at wlrfch the 

 pupa is escaping from the ovary, the pollen of the anthers of the male flower- is only begin- 

 ning to be shed. It is evident therefore that the synchronism of the two events— the 

 escape of the insect and the maturity of the pollen— is an arrangement of much physi- 

 ological significance. In the sperms of lie us in which the arrangement ju fcdeseribe<l obtains 

 (and these are by far the majority), the perfeot female flowers are contained in recep- 

 tacles which are consecrated to themselves alone. In these* receptacles the flowers are all 

 perfect females. There is not a trace of a male or of a gall flower. These receptach 

 in many species, are perfectly closed from a very early stage, and yet in the majority of 

 cases everyone of the ovaries of the females they enclose contains, when mature, 



a perfect embryo. The exact way in which these female* are pollenised is a matter on 

 which I cannot pretend to throw 'any light. I can only state the problem. The mah 



are shut up from an early age with a number of females, the structure of whose < ,rans 



is unfavourable to pollcnisation. No pollen is produced by the males thai are hut up with 

 these females until all possibility of their becomin fertile with pollen has been jreclud I 



by the deposit within each of their ovarial cavities of the eg^: of an insect < >n the other 

 hand, a number of perfectly formed females, all well adapted ftf the ra lion of p»lUu, are 



shut up together in a receptacle which contains neither male noi ill Bowers, and to which 



it is from a very early stage apparently impossible for im cts bearing pollen to get acc< 

 Yet each of the females situated in such apparently disadvanta .corns circumstances bears 



a well-formed embrvo. No doubt the insect developed in the gall flowers in some 

 way conveys the pollen of the males to the perfect females imprisoned in the n< Ighbour- 



receptacles. But although one can understand that it is to tin advantage of tin 



ing 



insect to enter the receptacle containing the gall flowers, sine,. th« ) afford it 8U<h a 

 suitable nidus for its vgg, and that the mature ins* I in cscapin from the reo ptades ma} 



advertently carry along with it some of the pollen which the anthers are- then shedding 



J 



yet it is difficult to understand how the pollen ^ » removed is < my 1 into th. int rior 



of the receptacle containing the perfect females, and how these females are so umvc 



fertilised by it. 



This arrangement, by which the receptacles are practically diacious, -Main . as 



have said in a'large proportion of the species of Ficus. There is, however, a group of 



