Monotropa Glabra. 65 



the lime-twigs, inasmuch as these stand out from the 

 margin of the calyx in a somewhat oblique outward 

 direction; but then these insects are in the highest 

 degree welcome yisitors to the flowers of Cwpk&a 

 micropetala. 



In all the cases as yet mentioned it has been creep- 

 ing insects that are kept back from the flowers by the 

 viscid secretions. There are, however, other species 

 where flying insects are similarly shut out from the 

 nectar, when their visits would confer no advantage 

 on the plant. Such for instance is Monotropa glabra 

 Bernh., of which I give drawings (Plate I. fig; 30, longi- 

 tudinal section of whole flower; fig. 31, longitudinal 

 section of magnified style). The petals which form the 

 cylindrical coroUa of the above-mentioned Monotropa 

 are saccate at their base, and the thick firm tissue of 

 which these saccate portions are made secretes inter- 

 nally an abundance of nectar.^ The remaining and 

 pointed portion of the petals is, on the other hand, 

 made of soft tissue ; and these almost membranous ends 

 of the petals are closely applied to the end of the 



^ The crooked horn-like growths which project in pairs into 

 these saccular dilatations, and have been held to be nectaries 

 (Eichler, Bl. Diagr. 346), do aot secrete nectar. They form two 

 whorls, the parts of which alternate with each other, as also with the 

 members of the two whorls of stamens, and with the divisions of the 

 single whorl that constitutes the corolla. They represent abortive 

 stamens ; and the advantage that accrues to the flower from their 

 abortion consists probably in their preventing the nectar from 

 running out from the saccular dilatations, when the flower is in a 

 drooping position. 



