110 Trans. Acad. Sci. of St. Louis. 
males and workers, are abundant, while the workers are just 
beginning to appear. Accordingly, I regard the flower as 
adapted to bumble-bee females, which in fact are the most 
abundant visitors. But butterflies and humming-birds are 
also frequent and are efficient pollinators. The visitors men- 
tioned below were observed on 8 days, between May 19 and 
June 7 :— 
Apide: (1) Bombus separatus Cr. 9, s., freq.; (2) B. americanorum F. 
9, 8.,ab.; (3) B. virginicus Oliv. 8, s., one, rarely touching anthers and 
stigma; (4) B. ridingsii Cr., 8, s. and c. p., one 
Trochilide: (5) Trochilus colubris L. 
Rhopalocera: (6) Pyrameis huntera F.; (7) Papilo philenor L.; (8) 
Pamphila zabulon B.-L., v. quadriquina Scud.; (9) P. metacomet Hates ; 
(10) Eudamus pylades Scud.; (11) E. bathyllus S. -A. —all sucking. 
Now the tube, although 18 mm. deep, admits small bees for 
about 7 mm. and the nectar rises as high as 11 mm., so that 
small long-tongued bees can lower the nectar several mm., 
although not able to drain the tube. As a consequence, the 
nectar is often sought by small, or medium sized insects which 
never, or rarely, touched the anthers and stigma. Examples 
of such intruders are: — 
oe Apis mellifica L. 8, s., ab.; (13) Ceratina dupla Say 9, s. andc.p., 
3 (14) Coelioxys a Sm. (=dubitata Sm.) 9, s., one; (15) Bom - 
aie atriceps Lw., 
In addition to these, a number of small bees visit the flower 
only for pollen, alighting directly upon the anthers or upon 
the tip of the upper lip, whose hairs serve them as a foot-hold 
while collecting pollen. These bees only find what they seek 
when the flower is in the male stage, but since they can hardly 
tell that the pollen is gone until they have landed, they are 
quite apt to visit the flowers which are in the female stage 
also, As they approach the tip of the lower lip from 
below and in front, they are apt to strike the stigma before 
they land. At any rate, I am satisfied that they often 
effect cross-pollination and that the hairs on the tip of the lip 
are increased in number and size for their benefit. The case 
is interesting, since it shows how the flower might be enabled 
to dispense with its nectar-visitors and depend upon its pollen- 
visitors—either if the nectar-visitors should become unnec 
