1917.] Observations on Pollination in Alysicarpus. 291 



that with surprising results. I discovered that in this plain 

 the flower explodes without any insect visit or the applied Ion 

 of any external force. An observer may easilv see, if he watches 

 one particular inflorescence between 12 noon and 1 p.m., that 

 as the result of every explosion, a cloud of pollen grains is 

 thrown upwards and they may rise to a height of one to one 

 and a half inches above the exploded flower and then shower 

 down on the stigmas of the neighbouring inflorescences which, 

 as I showed you, are in most cases within the radius of an inch 

 or a little more from the exploded inflorescence. 



In some cases, the pollen from the numerous flowers of an 

 inflorescence may be drifted back to the stigmas of the same 



flowers. Since such stigmas have an equal chance of getting 



* O D X 



nates, and Xenogamy is effected. 



poll 



Now, one might ask what would happen if only one plant 

 is grown in one particular place. The answer is that such is 

 not the case in nature, and in such an exceptional case, there 

 being many open flowers on one inflorescence, pollen could be 

 carried either from one flow er to another or from one branch to 

 another branch. Here Geitonogamy is effected, which is more 

 advantageous than self-pollination. 



By examining side by side the flowers of A. rugosus and 

 A. vaginalis one could see that in the former the flowers are 

 brighter and the nectary is swollen out and contains nectar ; 

 but in the latter it is less coloured and the nectary is almost 

 functionless. In both, however, the pollen is sticky. So thi 

 might have been primarilv intended for some specialised insect 

 like Nomia ; but since insects which are necessary to carry out 

 this elaborate work perhaps are not in sufficient number-, the 

 plant has to resort to this sort of carrying out cross-polluuihon 



without any external agency. 



It would be interesting to know the reason why the flowers 

 of A. vaginalis explode freely without any external force, wnil< 

 those of A. rugosus, having an almost similar explosive mechan- 

 ism are at the mercy of the insects. Regarding this point l 

 subjected flowers of these plants to varying temperatures and 

 some interesting observations have been made which 1 Hope to 



continue. . , A 



It appears from the preceding account that all plants do 

 not depend entirely on an external agency for cross-pollina- 



tion. 



Since writing the above I have found the A. \ 



typ 



u«wc writing tne a-uuve j. u«»~ * , -l;*™, TViic 



of pollination-bv spontaneous explosion-in A. ™ 01 f fe J a ™£ 

 is interesting because the latter falls under my A . vagmaii 

 group, and the mechanism is exactly the one I should expect. 



• Handbook of Flower Pollination, vol. I, P»ge 38 



