Cavity closed by Perianth. loi 



the lower of which the nectar is stored. Such, for in- 

 stance, is the case with jiEchmea cmrulea and Soldanella 

 alyina (Plate II. fig. 76, longitudinal section of flower). 

 Still more peculiar is the arrangement in the several 

 species of Mgella, where the nectariferous cavities, 

 formed in the petals, are closed by moveable lids. 

 (Plate III. fig. 77, side view of such a petal of Nigella 

 elata, L. ; fig. 78, longitudinal section of the same petal ; 

 fig. 79, a petal of Nigella sativa, L., seen from above ; 

 fig. 80, view of the same petal after the removal of the 

 lid-shaped excrescence.) Each petal is here seen to be 

 hollowed out into a kind of pit, into which nectar is 

 secreted in abundance by the surrounding tissue. The 

 part of the petal beyond the pit forms two curious 

 divergent processes ; while the other, or basal part, is 

 reduced to a mere stalk, so that the whole petal comes 

 to have somewhat the shape of a spoon. At the point 

 where the handle is continuous with the bowl, the 

 petal gives off an excrescence which covers in the 

 whole nectar- cavity like a lid, closing it completely. 

 No animal, therefore, can possibly rifle the nectar 

 unless it be strong enough to lift up this lid. I have 

 seen ants that had crept up from below striving in vain 

 to make their way into the cavity. Our common honey- 

 bees, on the other hand, can raise the lid with perfect 

 ease. But then these bees are also of such a size that, 

 in visiting the flowers and making their way to the 

 closed nectaries, they must inevitably rub against the 



