POLEMONIACEAE 113 



l)ent. Sprengel, Lepidoptera. MacLeod, the moth Plusia gamma L,, skg. (Bot. 

 Centralbl., Cassel, xxix, 1887). Herm. Muller, 2 Diptera i. Conops flavipes L., 

 skg. (but scarcely reaching the nectar, its proboscis being only 4-5 mm. long); 

 2. Eristalis tenax L., po-dvg. Schletterer and von Dalla Torre (Tyrol, two bees 

 I. Anthidium strigatum Lir. ?; 2. Halictus smeathmanellus K. 5. Loew (Berlin 

 Botanic Garden), the Muscid Echinomyia fera Z,, as an unbidden guest. 



1936. P. reptans Michx., and 1937. P. subulata L. 



Visitors. Loew observed the honey-bee in the Berlin Botanic Garden. 



1938. P. setacea L. (=P. subulata L., according to the Index Keivensis). 

 (Francke, Inaug. Dissert., Halle, 1883.) Francke describes this species as pror 

 tandrous. Self-pollination by the wind or by insects is possible. 



588. Cobaea Cav. 



1939. C. penduliflora Hook. f. 



Visitors. A. Ernst states that this species is polhnated by hawk-moths 

 (Kosmos, Leipzig, vii, 1880, pp. 44-6). 



1940. C. scandens Cav, (W. J. Behrens, Flora, Marburg, New Ser., 

 xxxviii, 1880, pp. 403-10; Knuth, ' Bloemenbiol. Bijdragen ' ; Kerner, 'Nat. Hist. 

 PI.,' Eng. Ed. I, n, pp. 304, 384-5.) The flowers of this species observed by 

 me in the Botanic Garden of the Kiel Ober-Realschule were greenish-white 

 in colour when they opened, and therefore not very conspicuous. At first the 

 anthers are not ripe nor the stigma mature. The lower corolla-lobes gradually 

 assume a faint purple colour, but the whole flower does not become purple until 

 the anthers dehisce. The breadth of the corolla seems to me much too considerable 

 to make it probable that humble-bees are the pollinators of this plant in its native 

 country, Mexico ; and I think it far more likely that the larger humming-birds are 

 the visitors. 



Kerner describes the flower mechanism somewhat as follows. At first the 

 pollen-covered anthers are so disposed in the entrance of the flower that animals 

 trying to secure the concealed nectar must brush against and remove the pollen. 

 At this time the internal papillose surfaces of the three stigmas cannot be touched, 

 for they are closely apposed, and concealed beneath the anthers owing to the 

 shortness of the style. The filaments now elongate, so that the anthers are applied 

 to the lower margin of the entrance of the flower, while the style curves upwards, 

 and the stiginas diverge, taking up the position occupied by the anthers in the 

 first stage of anthesis. Should there be no visits from pollinating animals, autogamy- 

 takes place as a last resort. The so far nodding flowers become pendulous, and the 

 style and stamens curve more strongly, so that anthers and stigmas are brought into 

 direct contact. 



Visitors, Vide supra. W. J. Behrens says that humble-bees are the polli- 

 nators. 



1941. C. macrostemma Pav. (Herm. Ross, Flora, Marburg, Iviii, 1898, pp. 

 '25-34.) Hermann Ross states that the flowers of this species open in the evening, 

 and appear to be adapted for pollination by hawk-moths. Should insect-visits fail, 



