SHORT CUTS ВУ BIRDS ТО NECTARIES. 411 
openings and so to be of use to them for cross-fertilization, excepting in the 
case of individual flowers that happened, through inconvenience in their own 
or the bird's position, &c., to offer some difficulty. If these were insutt- 
ciently protected as well, they were often either pierced or the openings 
already made in them by the more indiscriminating birds were utilized. 
6. Protection took several forms—thin, pliable pedicels, massing of the 
flowers for mutual protection (a possible factor in the evolution of the 
capitulum), thickening of parts, and so on. 
7. Insects as well as birds tended to utilize the breaches made by the 
latter, and so probably in large part failed to counteract the birds’ dis- 
criminative influence. 
8. In most cases the eliminative effect, if any, of the damage was not 
traced. In two instances it was (for individuals) immediate and clear, 
flowers of a certain type being bodily removed. 
The observations were suggestive, but over-scanty, and the effect, if any, 
of the damage was insufficiently followed out*. They were fairly con- 
sistent, however, so far as they went ; and the fact that damage was confined 
to particular areas, often adjoining other areas in which it was absent or of 
another kind, and that such areas were not necessarily the same at different 
periods, is, I think, useful for its warning that where purely negative evidence 
is found, it should not be regarded as necessarily conclusive in matters of 
this kind. 
ADDENDUM.—March 24th, 1914. 
Since the above paper was read, Mr. Charles Oldham has most kindly 
called my attention to a paper published in * The Zoologist? for January 
1896, pp. 1-10. It is by Dr. John Lowe, and is entitled * Notes on a 
newly discovered habit in the Blackeap Warbler and other birds." 
His observations were carried out in Tenerife, in the Grand Canary, 
* I have, amongst other shortcomings, not yet attempted the very necessary experiment 
of excluding the birds from the various flowers they most commonly visit. Мг. M. S. Evans 
published in * Nature’ (1895, Jan. 3rd, р. 235) an interesting account of such an experiment, 
He protected from eighty to a hundred healthy flowers of Loranthus Kraussianus, Meissn., 
from their Sunbird visitors (Cyanomitra olivaceus, Shelley)--but one would judge from the 
account that he probably excluded insects too,--and he * found that when thus protected ... 
none exploded, and, as a consequence, not a single flower within the bag set seed. They 
seem to be quite sterile without outside help: the anthers dehisce, but at a level below the 
capitate stigma, and as the corolla-tube is generally upright the pollen is lost even as a 
self-fertilizing agent." He came to the conclusion that the plant depended on the Sunbirds ; 
for bees, though they followed the birds, seldom themselves caused an explosion. He came 
to a similar conclusion with regard to Loranthus Dregei, Eckl. & Zeyh., in which species 
the Sunbird-caused explosions were so violent as to send not merely the pollen but the 
whole anther all * flying into space." 
