3 5 J) 



AUTOGAMY. 



coherent^ wliilst a further condition, which ^^■onld also render pollination impossible 

 consists in a lateral inclination or sharp inflection of the style Avhioh removes th* 

 stigma ont of the way leading to the honey. The eight anthei^ tJien stand in front 

 of the spots where honey is to be obtained, and liberate their pollen in twra, A 

 little later — half an hour in Evening-prinu-oses, and 24 hours in the laro^j-flowei-ed 

 species of Willow-herb — the style straightens itself aaid t^ikes up a centi-al position 



in tlie flower, whilst its four 

 branches open back and present 

 themselves in the form of a 

 cross in front of the entrance to 

 the honey. The stigmas remain 

 in this position for a short time, 

 and there is no need to enter 

 into nioi"e det^iil to make it evi- 

 dent that cixiss- pollination may 

 now be ett'eeted by the humble- 

 bees which come in seareh of 

 honey and bring witli tliem ft 

 store of pollen from youngvr 

 dowers. Soon after\\*ai'ds, the 

 four stigmas boml or roll hack, 

 bringing their receptix'e tissue 

 into contact with the pollen still 

 adhering to the anthers (see 

 fig. 800. the lower flowei"s), This 

 act o'i autogamy is usuidly pro- 

 nto! ed also by tho stamens heoom- 

 ing rather more erect and hy mi 

 indection of the stalk-like infe- 

 rior ovary in a gentle curve to- 

 wards the ground, the result of 

 which is that the tloAvei-s nod, 

 ■/.('. are half-inverted. 

 Of the Ranunculacefe, a few species of Love-in-a-mist (NigoUa) exhibit the same 

 kind of contrivance. The flowers are protaiudrous. The first event to take place 

 after the expansion of tho sepals is a beiuling of the stamens in regulai" sequence 

 towards the periphery of the flower, whereby the open anthers are posted just 

 above the nectaries full of honey, Insects coming in searoli of honey must inevitably 

 rub against the anthers in that position and dust themselves with the pollen. 

 After the stamens have all accomplished these moven\ents, the styles, which have 

 hitherto stood stiSly erect and stationary, enter upon an active pha^e and bend 

 outwards until their terminally-placed stigmatio tissue, which, nieantimo, has bo- 

 come mature, rests over the nectaries. In this position the stigmas are oei'tain to 



Fig. 300.— Autogamy In the llowoi-a of tllo WlUow-llorb 



