PART III. ] THE MECHANISMS OF FLOWERS. 337 
outer surfaces ; finally they separate and display their inner sur- 
- faces (which are smooth, but capable of fecundation) to the touch 
of visitors. Self-fertilisation cannot occur. 
Hymenoptera—(a) Apide : (1) Bombus lapidarius, L. % ; (2) B. silvarum, 
_L. %; (3) B. muscorum, F. § ¢; (4) Halictus quadricinctus, F. 9 ¢; (5) 
_ H. rubicundus, Chr. ¢, all s. ; (b) Vespide: (6) Polistes gallica, L., and var. 
_ diadema, ab., s. See also No. 590, 111. 
_ Fig. 118.—Echinops spherocephalus, L. 
1.—Flower, at close of the first (male) stage. 
2.—Ditto, in second (female) stage. 
3.—Section of style and corolla-tube around it. 
a, filaments ; b, anthers; c, brush on style; d, stigma; e, nectary. 
_ chinops Ritro, L., was found by Delpino to be visited by a 
- sand-wasp, Scolia bicincta (178). 
«241, CARLINA ACAULIS, L.—In this plant the involucral bracts 
play a more important part than usual. The outer ones are armed 
with such strong spines that, in connection with the spiny leaves, they 
form a strong safeguard against any attempt to devour the plant. 
The inner ones help to thake the flower conspicuous by day, and 
t night and in rainy weather close in over the flower to protect it 
from wet. and cqld (609). 
The opening and closing of the capitulum in Carlina and other 
Z 
| = 
| ee 
