390 МВ. С. Е. М. SWYNNERTON ON 
a moderately strong wind to spill the ripened seeds out of the often more or 
less upward-pointing calyces that contain them: and Leonotis frequently 
grows in situations that are sheltered from wind. Buta bird, attracted by 
the flowers below and suddenly flying to them, is capable, by the swing it 
imparts to the vertical stem, of scattering the seeds. I have seen instances 
of this, and have verified it by experiment. 
Damage by birds: The individual calyx at the flowering stage should not 
ba difficult to pierce, and quite early in my investigation of the plant, as the 
result of examining a considerable number of the heads, I found many 
instances of successful piercing. It was always the typical sunbird 
puncture, and was probably the work of sunbirds, though, as Mr. Guy 
Marshall has suggested to me, it may not always һе easy to distinguish this 
from the work of Xylocopid bees. In all these cases, however, the sphere 
was defective, leaving the bases of individual flowers exposed, and it was 
these lowers, and these only, that had been pierced—in every case on the 
exposed surface. I never in these earlier cases found an instance of such 
piercing where the flower-ball was normally compact and spherical, though 
1 broke up and examined a large number. All were, however, within a 
single limited area. Later, а few hundred yards away on the outskirts of 
the Chirinda Forest, I obtained the following observations :— 
« June 2nd, 1913. Watched for some time on the outskirts first Antho- 
threptes hypodilus (Jardine) Gadow, then Cinnyris niassæ, Reichw., both males, 
entering flowers of Leonotis mollissima—in practically every case from above. 
I was within two yards, the birds not seeing me. Mostly they perched 
above the flower-ball, in a few cases below, but they nearly always entered 
by an artificial opening in the side or roof of the (lower. Very rarely the 
end of the corolla came against the bird's throat, even when, perched below, 
it was entering by an illicit opening ; and here the stigma probably, and the 
anthers just possibly, may sometimes have come in contact with the bird. 
I took and examined two stems with twelve flower-balls, all of which I had 
watched the birds visit flower by flower. These showed 56 pierced flowers to 
33 unpierced. ` In only one verticilaster was there a preponderance of un- 
pierced flowers (6 : 5). In this one the flowering row was relatively (but not. 
very) low in the ball and therefore harder to reach from above. In some 
ases considerable force had appeared to be used, the bird going through the 
actual action of ripping ; but for the most part previously-made opgnings, 
already with browning edges, were utilized. Where the calyx as well as the 
corolla was pierced, the slit in the corolla was nearer the base than the corre- 
sponding slit in the calyx. This was natural.” 
“June 3rd. Visited yesterday's Leonotis clumps. Fewer birds, but 
watched a female and later a male Anthothreptes hypodilus visiting the 
flowers. As yesterday, they perched mostly above and (to-day) invariably 
entered wrong. The male entered one many-flowered ball from below. 
