FLOWER AND FRUIT 169 
4. In the pansy (Fig. 107) ‘the stigma is near the 
top of the style in a depression below which protrudes 
horizontally a little shutter or flap. The bee alights 
on the front petal, and to secure the nectar thrusts 
its tongue into the spur of the petal where, on 
prolongations of the anther connectives, the nectarics 
he. In so doing, the insect first pushes against the 
upper side of the shutter. Its tongue then passes 
down, picking up some of the pollen which is shed 
into the spur. On withdrawing its tongue the bee 
closes the shutter upwards against the stigma so that 
the latter is protected from self-pollination. On 
pushing into another flower it deposits the pollen from 
the first on the upper side of the shutter. When the 
insect withdraws, the shutter is again pushed upwards 
and the pollen upon it deposited on the stigma. Thus 
cross-pollination takes place. 
5). In the salvia (Fig. 108) there are two stamens, 
each bearing only one anther lobe. The connective is 
greatly prolonged and terminates on the lower end in 
a large flattened body. The bee in pushing into the 
flower presses against this flattened body. The whole 
mechanism acts as a kind of lever with the tip of the 
filament as the fulerum. The pressure against the 
flattened body causes the anther lobe, which is situated 
at the end of the other arm of the lever, to be depressed 
and strike the insect’s back, which, in consequence, 
becomes dusted with pollen. The insect withdraws 
from the flower without touching the stigma. In more 
mature flowers the style curves down, so that au insect 
visiting such a flower brings its back into contact with 
the stigma, and thus effects ecross-pollination. 
6. It is among orchids that the most marvellous 
pollination mechanisms are found. In the different 
New Zealand species there is nothing very remarkable, 
but the pollination of Pterostylis (Fig. 109), so well 
described by Mr. Cheeseman, is worth careful study 
