300 botanical gazette. [ December, 



Lepidoptera — Rho-palocera ; (16) Colzas -philodice Godt. 

 S-phingidcB : (17) Hemaris thysbe F. — all only sucking except 



7-9 and 15. 



At Madison, Wis., between May 13 and June 1, Prof. 

 Trelease found as visitors : Nomada bisignata Say, N. artic- 

 ulata Sm., Angochlora -pura Say, and Andrena sp., all suck- 

 ing- 



Imfatiens* fulva Nutt. — The flowers of this species, and 

 of the next, are male in the first stage as is well known. The 

 anthers siit out a great quantity of pollen when struck by a 

 bee, and the stigma is receptive after the anthers fall. Com- 

 pared with I. pallida this plant shows three peculiarities 

 which I think favor humming-birds, viz.. the red color, the 



small landing-place, and the longer and narrower posterior 

 sepal. The landing is about 6 mm. long and 15 mm. wide, 

 while in L pallida it is 12 mm. long and 25 mm. wide and 

 forms a more convenient resting place for bees. However, 

 the form of L fulva so closely resembles that of L noli-tangere, 

 which was developed beyond the range of humming-birds, 

 that it can hardly be explained as a result of bird selection. 

 It originally must have had differences which led the birds to 

 prefer it to L pallida. There is one peculiarity, however, 

 which may have been produced through the influence of birds, 

 and that is the accumulation of red spots on the original 

 ground color. I have elsewhere expressed the view that ir- 

 regular bird-flowers were originally modified by bees 7 and 

 have been usurped by birds. From its color, and from the 

 fact that humming-birds are the principal visitors, I regard it 

 as a bird-flower, although bees and butterflies also occur as 

 guests. 



The posterior sepal is about 22 mm. long, and its spur, 

 which is commonly coiled upon itself, is about 10 mm. 



Visitors : Birds— Trochilidcz: ( 1 ) Trochilus colubrls L.. 



ab. 



Hymenoptera— Afida: (2) Ap/smc////ica~L. $ . s. andc.p. 

 Snyder's 8 statement that it can not effect crossing is not true 

 in my neighborhood ; (3) Bombns virginicus Oliv. S . s. and 

 c. p. ; (4) B. americanorum F. $ % , s. ; (5) Mclissodi* bt- 

 maculata Say ? , s. ; (6) Megachile brevis Say 9 , c. p.. hangs 

 under the anthers so as to bring her abdominal scopa in cott- 



«On the literature of the gemis see Trelease : 1. c., 102. 

 'Bot. <\\/.. xiu. 228. 



•Am. Nat. xiv. 126. 



