PART III. | THE MECHANISMS OF FLOWERS. 487 
353. STACHYS PALUSTRIS, L. (178, 702).—The flowers differ 
from those of the foregoing species in the following points: the 
tube is only 8 to 9 mm. long, the outer (lateral) pair of stamens 
are of equal length with the inner (median), the anthers of the 
lateral pair lie, when the flower opens, in front of the median pair, 
and have already dehisced while the latter are still closed; in 
course of time they bend outwards and are detached by the median 
ones which now come to maturity. Finally, the end of the style, 
whose stigmatic branches now diverge, curves down between the 
median anthers; and the stigmas, if insect-visits have failed, 
come in contact with the pollen even more frequently than 
in S. silvatica. | 
Visitors: A. Hymenoptera—Apide: (1) Bombus silvarum, L. % (10) ; 
(2) B. agrorum, F. § (10—12) ; (3) B. terrestris, L. $, (7—9); all three 
sucking normally, not excepting B. terrestris, whose proboscis is too short for 
Stachys silvatica! B. Diptera—Syrphide: (4) Rhingia rostrata, L., s., now 
and then effecting fertilisation ; (5) Melithreptus teniatus, Mgn., fp. C. 
Lepidoptera—(a) Rhopalocera : (6) Pieris brassicae, L. (15) ; (7) P. rape, L. ; 
(b) Noctue : (8) Plusia gamma, L., all three ab., s. 
Stachys germanica, L., according to Mr. T. Whitelegge, is 
gynodicecious (774). 
354. StacHys BrETonica, Benth.—The corolla-tube is 7 mm. 
long, smooth internally in its lower honey-containing part, but 
lined above with erect hairs. The part of the corolla within the 
calyx is narrow and directed obliquely upwards; beyond the calyx 
it becomes almost horizontal, remaining of the same width (about 
2 mm.), and it divides into a trilobed under lip, and a flattened 
“upper lip almost vertical towards its extremity. There is no need 
here for a wide entrance to receive the bee’s head, on account of 
the shortness of the tube. The curvature of the tube corresponds 
to the natural curvature of the bee’s proboscis. 
The flowers are distinctly proterandrous, but the possibility of 
spontaneous self-fertilisation is not excluded. Shortly after the 
flower opens, the anthers, which bear a row of white beads on their 
upper surface, dehisce, while the stigmas lie between and slightly 
behind the shorter anthers. Although the style has not nearly 
attained its full length, yet its stigmatic divisions diverge almost 
as much and are almost as well provided with papille at this 
stage as they are subsequently, and pollen placed on the papille 
1 Jn Sideritis romana, L., according to Delpino, these white beads apply a sticky 
substance to the insect’s proboscis (178, pp. 144-146). 
- 
