Cuphea Micropetala. 63 



-continuous with the style, presents a swelling, which is 

 closely applied to the upper side of the calyx-tube; 

 (Plate I. fig. 28, longitudinal section of flower ; fig. 29, 

 transverse section, at right angles to the axis of flower at 

 the base of the triangular style). As the ovary is on 

 either side in close apposition to the calyx-tube, the 

 nectar is, as it were, corked up inside the saccular dilata- 

 tion of the calyx. But on either side of the ovary, 

 to the right and left, as may be seen in fig. 29, is a 

 furrow, which widens out anteriorly like a funnel, so as 

 to form a passage, half a millimetre in width, leading 

 into the cavity behind the ovary; a cavity which is 

 not only itself full of nectar, but also usually overflows 

 into the passages. Flying insects that would get to 

 the nectar, and whose visits, owing to the marked 

 proterandry of the flowers, would promote intercross- 

 ing, must insert their trunks through these passages. 

 But it would naturally be far from agreeable to them 

 to find the mouth of the passages swarming with ants, 

 licking up the nectar and blocking up the entrance ;^ 

 and therefore it would be a disadvantage to the plant 

 to have its nectar accessible to these wingless creeping 



1 If ants are attacked with a fine bristle, they do not as a rule 

 take to flight, but stand on the defensive, seize hold of the bristle, 

 and work at it with their jaws. They act in a similar way if im- 

 prisoned in a small bottle. It is therefore very probable that ants, 

 when disturbed in their enjoyment of the nectar in a flower by the 

 intrusion of an insect's proboscis, seize hold of the proboscis and 

 bite it. 



