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pollen and in doing so is able to stimulate the stigmatic surface and to effect 

 cross-pollination. The two small Indian bees, Apis mdica a,nd. A. florea, visit 

 the flowers for pollen left by the other insects but are not heavy enough to 

 work the mechanism and therefore have no influence as pollinating agents. If 

 the flowers are not visited by insects, the continued elongation of the filaments 

 of the long stamens presses the pollen mass round the stigma. Both cross 

 and self-pollination are therefore possible. The ovate anthers do not burst 

 until their work of supporting the pcllen mass in the carina is completed 

 towards the end of the first day of opening or on the morning of the second. 

 The arrangements for pollination therefore follow for the most part those 

 described by H. Miilleri in the case of Lupmus luteus L., but the piston 

 mechanism is in Crotalaria juncea combined \Aith the brush system of Pisum 

 sativum L. 



Fertilization. The arrangements at first sight suggest the possibility of 

 self-pollination as well as cross-pollination but the former does not occur if the 

 flowers are protected from insects. If flowering takes place in muslin cages, 

 the pollen is liberated and forced all round the stigma in the usual manner 

 but no subsequent setting takes place. The flowers last for four or five days 

 and then gradually fade. If, however, a branch is led outside the net into the 

 open air, setting takes place normally and pods and seeds form in the usual 

 manner. These results suggest that the stigma must first be stimulated by 

 contact with the insect before the pollen grains can germinate. To confirm 

 this, some experiments were made in 1916 in which the stigmas were rubbed 

 with rough cardboard before selfing. In all cases the experimental plants were 

 covered with netting before flowering time and in two cases control inflores- 

 cences were allowed to flower freely outside. The results are given in the 

 following table : — 



1 H. Miiller. Fertilization of Flowers, 1883, pp. 187 and 211. 



