AVTOGAMY BY THE HEXDIXG OF THE PISTIL. 



351 



salad (VitlerianeUa AunciiJa. V carinata, kc.\ and of the non-twining species of 

 Houevsuekle (Loniccra alpigi'na. L. nigra, L. Xi/lostcum) are protogvnous, aud the 

 stvle is so placed when the corolla opens that it-s stigma must of necessity be brushed 

 bv insects as they make their way to the receptacle. There is evidently at this stage 

 no possibility of auy but cross-fertilization. Ltiter on, when the anthers open and 

 expose their pollen, the stigma is taken quite out of the way, the style becoming 

 bent downwards or to one side, so that the stigma cannot come into contact with 

 fuit.hei"S of the same flowei-s either spontaneously or through the agency of insects. 

 Not till the flowex-iug period is nearly o\er does the style return to its original 

 position: when this happens, the stigma is raised by the straightening up of the 

 stvle. and is pressed ag-;iinst the anthei-s, whicli are still coated with pollen. The 

 flowers of the Martagon Lily {Liliwni Alarta-gou) are nodding, aoid have their 



Fii:, 299, — Autogamy effected tiy means of an inflection of tlie style, 



' Flower of Ttiejirle.' ^liftwi in the first stage of its development - The same in the l.i«t stasre of development s fl. « er of 

 Jfcnfj.] Pri^'trt) in the first stjvjre of development ^ The s.*mie in the List sl.ije of development '^ Stis^nia of Morina 

 covered with pollen from anthers belonging to the ssuue flower. « Flower of E:iphmi!ia minima in the tirst staire of 

 development " The same io the last stage of development All the figures slightlj- magnified. In figs. -. s, «, « ami : tlie 

 front part of the flower is eut .a« ay 



perianth-lobes strongly reflexed. In each petal there is a groove which is roofed 

 over aud closed in the middle by two coalescing rims, so that the honey stored in 

 the groove can only be sucked out by insects at the two extremities where the 

 groove is open. The flowei-s are protogynous, and, when thej- are newly open, the 

 style is straight and holds its stigma in such a position that it is sure to be touciied 

 by insects sucking honey from the inner orilice of the gi-oove. As the anthers are 

 still closed at this stage, only foreign pollen can be affixed to the stigma. Siibse- 

 (juently dehiscence ensues, and the position of the anthei-s in front of the external 

 orifice of the groove ensures tlieir pollen being brushed oti" by insects trying to suck 

 the honey at that end, whilst the stigma is left tmtouched by them. In this second 

 stage of the tlower's development the style begins to bend a little to one side, ;ind, 

 towai\is the end. the curvature increases to such an extent that the stigma comes 

 into contact with one or sometimes two of the anthei-s, and dusts itself with pollen. 

 Often enough, it is true, tlie stigma misses its mark, and in consequence autogamy 

 IS not so certain to occur in the Martaoon Lilv as in most of the other cases. It 



