Cavity closed by Gynescium. 107 



part of the periantli, and completely closes up the three 

 nectar-pits at the bottom of the flower. None but 

 strong insects, — insects therefore of such a size that 

 they mustj in getting to the nectar-cavity, rub first 

 against the stigmas and then against the pollen (which 

 is exposed in the extrorse anthers that project above 

 and in front of the gibbous perianth), — are able to 

 separate the stiff perianth- leaves from the ovary, and 

 to insert their proboscis into the nectar-pits. In Sedum 

 maximum again it is the thick carpels that over-arch 

 the small nectaries at the base of the petals, and that 

 protect the nectar which these secrete. Lastly, a pre- 

 cisely similar arrangement occurs in the genus' 

 Hypecoum. In Hypecoum procumheTis (Plate II. fig. 

 66, the whole flower; fig. 65, one of the inner petals 

 seen from the side turned towards the ovary) the 

 nectar is secreted in a little depression just above the 

 claw of each of the two inner petals. Immediately 

 above this depression the petal gives off a very 

 peculiar appendage, just as in Ranunculus glacialis, 

 on which pollen is deposited above.^ Not only when 

 the flower is closed, but also when it is expanded, 

 which in fine weather is the case from eight A.M. 

 to five P.M., these two appendages run parallel to 

 the ovary, in contact with, and, as it were, embracing 



^ The part played by these structures in the fecundation of the 

 stigma, and especially in the antogamic fecundation which occurs 

 when the flower remains closed, cannot be described here in 

 detail. 



