3;U AI'TOCJAJIV. 



visit a tlower, tlio antliors ;iro still Tull ol' pollen nt tlio I'loso of its llmvoriiiif povioil, 

 and being then displaeed let Ml their ]iolli>n iijion tiie slightesl^ vilinilion tif tlH\ 

 penileut blossom, or e\'en when it is quite still. The pollen I'lills sti-Might down mul 

 is ca.no'ht by the stigniti below. 



The proeess above deseribed is only observed to fake place in piMident iUnvors 

 where the pollen is of llonry eonsist.i>ney and the stamens ar(> united into a coniciil 

 cap. Flowers borne on luirizontal stalks, and i'aciiio- sideways, may exhibit, the 

 same phenomenon in eonneetion with si'paraie st.ainiMis, Only an in\porl>mit 

 circumstance in this case is that some of the anthers shotdd be exactly over tlio 

 stigmas at the time ol" dehiscence, \^'itll n, view to cross-l'ertili/.aiion, lateral flowiirs 

 of the kind are protogynous, niul have tlieir anthers closed wluMi t.he buds open; 

 but later on the a,nthers dehi.xce, and a. poi-tion of t,lu> pollen then liluMvited falls 

 out, owing to the contrract-ion of the walls of tlu" aidliers, ami besprinkl(>.s tilio 

 stigma of the same tlowi'r. This n\ethod of anlogiiniy has been observcil in piir- 

 ticular in the tlowers of Tojichiui and tlie Hog Asphoili>l (A'liiihcci ii iii). 



Even in upright Mowers autoga,my sometinies takt's place in the second half 

 of their time of tlowering throiigh a fall of pollen, and thali wit.hout any change 

 of position on the part of petals, stamens, or s|.yl(>. To mak(> cross-fertiliznlioM 

 possible, in the fii'st instance, llowers of this kind a,re protogynous. SnliscMpMaitly, 

 after the dehiscence of the anthers, a ]ioi-tion of the crundily jiollen 1i(>comiph 

 detached, and is deposited on tlie stigma, below. In the casi^ of erect llowers willi 

 funnel-shaped corollas, the pollen slijis down the smooth sloping wall of the funnel 

 to the stigma, and it is not essential for t.he anthers to stiind vci'tically above t.lio 

 stigma, since the corolla a.cts as a sort of conduit for the pollen. The biliic 



(Syringa) is an example of the ])la,nts of this ca.tc^gory. It is also reniarkahlo for 

 the fact that, though its llowers are only ])rotogynous for a \i'\-y short t.iino, yd., 

 for one or two days aftci- the dcdnscence of the a.nthoi's, autoga.iiiy cannot, take 

 place, because the anthers face outwards. So long as tlui anthers a.i'(\ in tliJH 

 position the pollen cannot be transfcirrcMl without extra.neons aid to the corolla- 

 tube; it is not till later on, when the anthei'a get covered all round with iiollcii, 

 owing to the gradual shrinkage of thoir walls, that some of the ]iollen drojw on to 

 the stigma standing undenu^a.th in the tube, of the funnel. 



Very often in erect or oblitpudy ascending llowers autogamy is hrouglit abniit 

 by an elongation of the filaments during the. ])(^riod of llowering, tlie result luiiiig 

 that the anthers, which are, origina.lly lower down tha.n tln^ stigina.s, a.i'c elcva.tcd 

 to the same level as the latter, and are thus (Mia.bled to dejiosit tliiMr jiollen npon 

 them. Most of tins species belonging to this group are protogynoiiH; the lilaineiitH 

 are erect, and are either adlici-ont or (dse parallel to the ovary or style. Al. lirHt 

 the anthers are so far from the stigma that the pollen would not of iliHolF diiHt 

 the stigma, in the same llowor, but the 8ubH0(|nent elongation of the filanii^ntH 

 is so regula,ted as to carry the a,ntherH to the Hame level as the stigma. Iiy U\o 

 time they are coated with pollen, The. antlu^rs then adhere to tJie receptive 

 stigmatic tissue, and autogamy is the result. The following a.re inst,a.nc,oH of plaritn 



