parr ur.] THE MECHANISMS OF FLOWERS. 335 
also; these occupy the same position in the male capitulum as 
the sexual florets in the female, and they resemble the latter in 
the complete absence of a nectary and of stamens, in the possession 
of a style, and in the very narrow tubular corolla. They are 
obviously degenerate female florets, which occupy in reduced 
numbers and in a functionless condition the place that in the primi- 
tively hermaphrodite or gynomoncecious capitulum was occupied by 
functional female florets (609). 
_ Homogyne alpina, Cass., is gynomoneecious. The marginal 
female florets secrete no honey and have lost all traces of stamens, 
-and their corolla is reduced to a short and narrow tube with a 
more or less insignificant remnant of a ligulate limb. I have 
seen the plant visited by five Diptera, one humble-bee, and 
twenty-eight Lepidoptera (609). 
237. ARNICA MONTANA, L. (Sld.) :— 
_ Visitors: A. Hymenoptera—Apide: (1) Apis mellifica, L. $, s. and 
¢.p., ab. ; (2) Bombus pratorum, L. $, 8. ; (3) Andrena Gwynana, K. 9,c.p. 
B. Diptera—(a) Bombylide: (4) Anthrax hottentotta, L. ; (b) Empide : (5) 
Empis tesselata, F., s., ab. ; (c) Syrphide: (6) Eristalis horticola, Mgn. ; (7) 
E, arbustorum, L. ; (8) E. nemorum, L., all three very ab., 8. ; (9) Syrphus 
‘Tibesii, L., ab.; (10) S. umbellatarum, Mgn. ; (11) Volucella bombylans, 
I, te (12) V. pellucens, L., all s. and fp. (d) Conopide: (13) Sicus 
ferrugineus, L.,s. C. Lepidoptera—Rhopalocera: (14) Argynnis Aglaia, L. 
(15) Vanessa urtice, L.; (16) Vanessa Io, L., all threes, D. Coleoptera—(a, 
| Lamellicornia: (17) Trichius fasciatus, L. ; (b) Chrysomelide : (18) Crypto- 
cephalus sericeus, L. 
i The structure of the flower is described in my Alpenblumen. 
On the Alps I have found it visited by three beetles, seven flies, 
‘four humble-bees, and thirty-four Lepidoptera. 
238. SENECIO JACOBHA, L.—Sixty to eighty florets, each con- 
‘sisting of a tube 2} to 3 mm. long and a throat equally long, are 
‘united into a disk 7 to 10 mm. in diameter; twelve to fifteen 
radiating marginal florets increase this diameter threefold. The 
‘style has the same characters as in Tanacetum. 
Visitors : A. Hymenoptera—(a) Apide: (1) Apis mellifica, L. 9, s. and 
ep. ; (2) Bombus lapidarius, L. § ¢, ep. ands. ; (8) B. pratorum, L. § ¢, 
ep. and s.; (4) B. campestris, Pz. ¢,s.; (5) Andrena fulvicrus, K. 9, cp. 
(6) A. denticulata, K. 9, ¢.p. ; (7) Halictus cylindricus, F. ¢; (8) H. albipes, 
'F. ¢; (9) H. maculatus, Sm. ¢; (10) H. nitidus, Schenck, @, all s. ; (11) 
/Nomada varia, Pz. 9, very freq. ; (12) N. zonata, Pz. 2; (13) N. fulva, Pz. 
9; (14) N. ferruginata, K. 9, all s.; (15) Osmia spinulosa, K. 2, ep. 
