386 



AUTOGAMY. 



pollen lying on the lowest perianth-leaf or with that still sticking to one or other 

 of the anthers (see fig. 311 *). 



Of the plants in which autogamy is brought about by inflection of the pedicel 

 combined with inflection or folding of the ■petals, two groups will be taken here as 

 representing two different forms of the phenomenon. These groups consist of the 

 Violacea3 of the Melanium tribe and the stemless Gentians. The manner in which 

 the pollen is transferred to the stigma in Violets through the agency of insects has 



Fig. 311.— Autogamy resultiug from inflection of the pedicel combined with incliiKitmn ,,f the style to the place where the 



pollen has been deposited: AUium Chamtvufh/ 



1 Shows the aerial portions of tlie plant; nat. size. 2, 3, 4 Single flowers mth the front perianth-leaves removed; sliglitly 

 raaguifled. They are in the successive stages leading to autogamy. 



been already described on p. 280, and illustrated in figs. 279 ^- "■ ^ on p. 279. The 

 pollen thus deposited by insects on the slightly-projecting flap of the capitate 

 stio-ma is derived, of course, from other flowers, and the result of its transference is 

 a crossing between the flowers either of one or of two species. Autogamy is in 

 general scarcely possible in the Violet during the first part of the flowering-period. 

 If pollen is shaken out of the cone of anthers on to the proboscis of an insect which 

 is in the act of dusting the front surface of the stigmatic lobe with foreign pollen, 

 this new supply may, perhaps, be rubbed oflF on to the back of the stigmatic lobe as 



