1 



ON THE FERT1LIZATICLV 



Ot" tl Ml 



lior mtali) 



Wm S very •blirjuefr inclined to one another, and the deeper ones lying 



aparinir the date regarding receptacles in various stages of maturation 



.ub^uent'to the a^ce* of insects, it is very evident that, besides very great general increase 



in hoik (Plate I, fig*. 1, 2), there is a distinct tendency towards an unfolding of the 



receotacle The oetiolar orifice at the period of access of insects is normally more or 

 le.di.ti :ly craterform, with the larger opening directed towards the cavity, and the 

 ,1am.* surface, around it covered by somewhat oblique and almost erect bracts (Plate IV, 

 fj 2 ) In matmv receptacle* on the other hand, the widest portion of the orifice 

 lies externally, and the sides of the deeper portion, in place of being sloped, are almost 

 vertical the change in their inclination having necessarily induced one in that of the 



hracts springing 



Si 



from their surfaces (Plate I, fig. 2). The margins of the orifice 

 n fa t turned < ltwnr< s as maturation advances, the process causing a change in the 



direction of the bracts and mowing the depth of the plug. The mam determinant of the 

 c }„ i the ex e*" i growth of the gull-flowers in the peripheral area of the ostiolar 



upect of the earity, far, while the basal area of the male flowers remains almost 



,.««l#.,r*I th-il of the Brail-flowers is very greatly increased, and the accumulation 



maw i, 



masses of enlarged ovaries in the deeper part of the concavity where the ostiolar 



I <l<-nee masses "i vni.u 



an lat»i 1 faced of the receptacular cavity meet must evidently tend to force the 



rmer c itwanN, or, in other words, must tend to unfold the receptacle. The process 



causes little or no alteration in the dimensions of the internal orifice of the ostiolar channel, 



but tends to render the dimensions of the latter more or less uniform throughout. The 



iiceeltiifut of th ostiolar bracts by the male flowers in the mature receptacles is thus 

 i 4 due 1 iv appreciable extent to any contraction of the circular zone on which 

 the latter are sit iated, but merely to change of direction in its contours in association 



with great growth in the individual flowers. 



The in <e in thickness of the stratum of gall-flowers is enormous. This is mainly due 

 to tho bet that the in rease in bulk of the ovaries is altogether in excess of that of 

 the surface to which the pedicels of the flowers are attached, the result being that it is 

 no >oger } >8$ib!c for them to find space arranged in a single or double layer as they 



oi nail; w. re. and that they have to be packed away in many superimposed strata 

 (Plate 1 6g Plate IV, figs. 23, 26). Even this, however, would not give sufficient space 

 were it not that the surface of attachment at the same time undergoes a relative increase, due 

 to its no ui r remaining smooth and even, but becoming covered by alternate elevations 

 and dr pi rions. Until maturation approaches, the great growth in the peripheral 



all-flower stratum of the ostiolar face of the cavity causes it to rise above the level 

 th. c utral art occupied by the male flowers and ostiolar bracts, and to form an elevated 

 si uronnd it, and it is only at a late period that a central eminence is again formed by the 

 ultimate evolution of the mule flowers (Plate I, ficr. 2). 



At the peri I of Bccee. of the insects the receptacular cavity is empty, but shortly after 



...ce h. • b n footed fluid begins to make its appearance, and gradually accumulates 

 uutd the , mty u cntn y occupied; the accumulation becoming so considerable as to 



,-,ve «. to .officien tendon to cause a jet of fluid to escape on perforation of the 



r ptacular wall. 1 he fluid is of dark reddish-hrnwn ™lrv„„ a i n t • j 



' . . _ icuuibn orown colour, and has an alkaline reaction and 



a specific gravity ranging from 1111 to lll(v3 On fiU™±* i -. - 



-. \ f i r ° ° . J , aiioo. Unnltration it is almost transparent, but m 



' -, 2 ilT T 1 1 V S 1 C, °; dy ' ^ t0 th6 P resence «* --te reddish-brown particle, 

 ■ be. | .rt.de. appear to be due to macerative disintegration of the bracts and perianth, of 



