l8 9i-l Flowers a?id Inserts. 69 



them would try to reach the nectar in front, but failing, would 

 crawl down to the base of the flower and insert its tongue 

 through the slit, but most of them only tried to reach the 

 nectar through the slit. This is the only time I have seen a 

 bumble-bee obtaining nectar illegitimately. 



Augochlora pura and Halictus connexus also visit this plant 



for pollen, behaving as on the flowers of L, syphilitica. 



Since the flowers of Lobelia are intended to be visited by 

 insects entering below the stamen tube it is an imperfection 

 that the tube has openings between the bases of the upper 

 filaments, for this allows improper visitors to steal the nectar 

 through the slits in the upper side of the corolla. Trelease 

 saw Augochlora pura treating flowers of L. erinus in this way 

 and I have observed the same thing in L. leptostachys and 

 L. cardinalis. 



Lobelia cardinalis x syphilitica. — Very many plants of the 

 two preceding species grew together in a large patch. The 

 ruby-throated humming-bird passed by L. syphilitica and 

 only visited L. cardinalis. The bumble-bee^ visited L. syphi- 

 litica regularly, only stealing the nectar of L. cardinalis in the 

 cases indicated; and they might not have done so, if they had 

 not been drawn among them by L. syphilitica. 



The insects which occurred on both species and which 

 effect hybridization are Bombus americanorum, Augochlora 

 pura, Halictus connexus and Papilio philenor. 



Among the plants I found nine specimens of the hybrid. 

 The corolla is shorter and broader and the lobes shorter and 

 firmer than in L. cardinalis, and is described by Schneck 1 as 

 of a deep reddish or crimson-purple. There is abundant nec- 

 tar, but the others seem imperfect. 



Twice I saw Bombus americanorum visit the flowers in the 

 regular way, showing that it could reach the nectar easily. 

 This led me to wonder if the humming-bird would visit the 

 hybrid. Seeing one alight upon a limb over my head, I drew 

 back and was rewarded by seeing him come down and visit 

 the hybrid along with L. cardinalis. It was interesting to ob- 

 serve that, while Bombus americanorum could not suck the 

 nectar of L. cardinalis properly and humming-birds did not 

 visit L. syphilitica at all, the nectar of the hybrid was easily 

 accessible to the one and its colors were attractive to the other. 



l Bot. Gaz. iii, 35. 



