FERTILISATION OF VARIOUS FLOWERS BY INSECTS. 167 
ing towards the terminal opening (fig. 6). These hairs answer 
to the so-called pails collecteurs in the composites : they 
sweep off the pollen, so that when the style is protruded its 
exposed portion — which alone is hairy — is seen thickly covered 
with the grains. None, however, are seen on the stigma ; for, 
the style being longer than the stamens, this lies beyond the 
anthers, and the movement only separates them still more. The 
viscid surface of the stigma is moreover turned away from the 
anthers, so that any grains which may drop from them acci- 
dentally will not light upon it. 
The weight of the bee, then, causes a viscid terminal stigma, 
succeeded by a pollen- smeared style, to protrude from the 
carina, and both come into contact with the upper surface of 
the insect. The stigma strikes it first, and as the bee pushes 
•deeper into the corolla the viscid surface is rung along its body 
from before backwards, and will inevitably carry off any pollen 
which may be there. For not only is the stigma viscid, but it 
is set round with a brush of fine hairs, which assist in collecting 
the grains. These are truly polls collecteurs, and must be 
carefully distinguished from the longer hairs on the style, 
which, as I have already said in speaking of the composites, 
would more fitly be called polls expulseurs. The surface 
which has been swept by the stigma immediately receives a 
fresh supply of pollen from the style which follows closely 
behind, and thus the bee leaves the flow r er in a condition suit- 
able for the fecundation of the next which it visits. 
Both humble and hive bees fertilise this Bean. Most of them 
have, however, learnt to get at the nectary feloniously by making 
a hole in the tube. In other similar instances it has always 
seemed to me that there was an evident reason why the bee 
should not go in at the natural opening. Either its proboscis was 
too short, or its head too large. But in this instance no such 
explanation is possible ; for while some bees visit the flower in 
the natural way, others of the very same species and of the 
same size avail themselves of the shorter cut, which involves 
less effort on their part. Whenever I have watched an indi- 
vidual bee visiting a succession of Bean flowers, I have always 
seen it visit them all in the same way. If it entered the first 
by the mouth, it continued to do so throughout ; if by the arti- 
ficial opening, it kept persistently to the same plan. It would 
thus appear that the habit is not an instinct, belonging by 
inheritance to the whole species, but is in each case the result 
of individual experience. As with the same experience some 
bees have acquired the habit and others have not, we must 
admit not only that these insects are intelligent, but that they 
differ from each other in their degrees of intelligence, some 
being slow in acquiring knowledge, others quicker. 
