CROSS-POLLINATION BY INSECTS 51 
like so much dry powder, and this should be noted 
carefully. 
The Hazel is another well-known instance, and it 
is particularly easy to scatter the grains by thousands 
from the catkins, which we know as ‘“ lambs’ tails.”’ 
The inconspicuous stigmas are less easily dis- 
covered, for they are not to be found on the catkins ; 
the illustration, however, will help us out of the 
difficulty and at the same time afford an example of 
stamens and pistils being upon the same plant but 
in different flowers, though probably no one but a 
botanist would talk about flowers in connection with 
either the Grasses or the Hazel. 
The clusters, into which they are grouped, are 
rather like small green pineapples with a crown of 
crimson stigmas instead of leaves, and if we are to 
satisfy ourselves that they really do produce the nuts, 
it will, of course, be necessary to watch them and to 
note the changes that take place from time to time. 
(c) Cross-pollination by Insects 
Let us now turn from the small, inconspicuous, 
scentless flowers of the wind-pollinated fraternity to 
the bright blossoms of such plants as the Poppy and 
the Corn Convolvulus, which woo, not the wind, but 
the insects. 
The former pays its guests for their services by 
feeding them with pollen grains which it produces in 
great abundance; whereas the latter tempt them with 
wages in the form of honey, brought to their notice by 
bright colours and sweet scents. I must point out, 
too, that the grains, which are not meant to be blown 
away, are adhesive instead of like dry dust, and this is 
very frequently the case with insect-pollinated plants. 
