PART III, | THE MECHANISMS OF FLOWERS. 539 
383. OrcHIS MoRIO, L. :— 
Visitors : Hymenoptera—Apide: (1) Apis mellifica, L. $; (2) Bombus 
muscorum, L. ; (3) B. lapidarius, L. ; (4) B. confusus, Schenck ; (5) B. pra- 
torum, L. ; (6) B. hortorum, L. ; (7) B. silvarum, L. ; (8) Eucera longicornis, 
L. ; (9) Osmia rufa, L. Nos. 1, 2,8 from Darwin ; Nos. 1, 3—7, 9 observed 
by me. 
384. ORCHIS LATIFOLIA, L. :— 
Visitors : Hymenoptera—Apide: (1) Apis mellifica, L. $; (2) Bombus 
senilis, Sm. ; (3) B. fragrans, Pall. (K.); (4) B. confusus, Schenck ; (5) B. 
hortorum, L. ; (6) B. lapidarius, L. ; (7) B. terrestris, L.; (8) B. muscorum, 
L. ; (9) Eucera longicornis, L. ¢; (10) Halictus leucozonius, K. 9; (11) No- 
mada sexfasciata, Pz. 9; (12) Osmia fusca, Chr. (= bicolor, Schr.) 9, all 
from my own observations. According to Darwin, O. latifolia is also visited 
by Diptera. I have found it visited by humble-bees on the Alps (609). 
385. O. MACULATA, L., seems to be visited chiefly by Diptera. 
Visitors: A. Hymenoptera—-Apid@ : (1) Bombus pratorum, L. % (once). 
B. Diptera—(a) Empide: (2) Empis livida, L.; (3) E. pennipes, both 
oberved by George Darwin, the former abundantly, the latter more rarely ;— 
in thrusting their tongues into the flower they cemented the pollinia to their 
eyes. (b) Syrphide: (4) Volucella bombylans, .L., very ab.; (5) Eristalis 
horticola, Mgn. (Sld.) freq. ; both got the pollinia attached to the fore-part of 
their heads. Nos. 1, 4, 5 were observed by me. 
Orchis maculata is visited by Cerambycide (Darwin, 165), 
and also by humble-bees (509). 
Orchis ustulata, L. and O, globosa, Li. are adapted for Lepidoptera 
by the very narrow entrances to their spurs; the latter species I 
found to be visited abundantly and exclusively by Lepidoptera 
upon the Alps (609). 
Orchis tridentata, Scop. is visited by humble-bees (590, 1). 
Tribe Cypripedine. 
386. CyPpRIPEDIUM CALCEOLUS, L.—The observations of Darwin 
(153 A.), Asa Gray (276), and Delpino (172, 178, 567), all refer to 
other and in some cases very different species of this genus. My 
own observations on C. Calceolus were published many years ago 
(565, 566), and have been repeatedly verified and extended since. 
I have observed five species of Andrena fertilising the flower ; 
viz. A. nigroenea, K. 9, A. fulvicrus, K. 9, A. albicans, K. 9, 
A. atriceps, K. 9 (= A. tebialis, K.), and A. pratensis, Nyl. 9. 
These bees, attracted by the colour and perfume of the flower, fly 
into the slipper-shaped lip and lick and bite the hairs lining its 
