Foxglove and Humble Bee 16g 
perpendicularly, and is smooth and pearly. The large 
humble-bee bustles in with the greatest ease, and uses these 
hairs as footholds whilst he is sucking the honey; but the 
smaller honey-bees are impeded by them, and when, having 
at last struggled through them, they reach the pearly, 
slippery precipice above, they are completely baffled. I 
passed the autumn of 1857 in North Wales, where the fox- 
glove was very abundant, and watched the flowers through- 
out the season, but only once saw a small bee reach the 
nectary, though many were seen trying in vain to do so. 
Great attention has of late years been paid by naturalists 
to the wonderful contrivances amongst flowers to secure 
cross fertilisation; but the structure of manycannot,I believe, 
be understood, unless we take into consideration not only 
the beautiful adaptations for securing the services of the 
proper insect or bird, but also the contrivances for preventing 
insects that would not be useful, from obtaining access to the 
nectar. Thus the immense length of the nectary of the 
Angrecum sesquipedale of Madagascar might, perhaps, have 
been completely explained by Mr. Wallace, if this important 
purpose had been taken into account. 
The tramway in some parts was on raised ground, in others 
excavated in the bank side. In the cuttings the nearly per- 
pendicular clay slopes were frequented by many kinds of 
wasps that excavated round holes of the diameter of their 
own bodies, and stored them with sting-paralysed spiders, 
grasshoppers, or horse-flies. Amongst these they lay their 
eggs, and the white grubs that issue therefrom feed on the 
poor prisoners. I one day saw a small black and yellow 
banded wasp (Pompilus polistoides) hunting for spiders; it 
approached a web where a spider was stationed in the centre, 
made a dart towards it—apparently a feint to frighten the 
spider clear of its web; at any rate it had that effect, for it 
fell to the ground, and was immediately seized by the wasp, 
who stung it, then ran quickly backwards, dragging the 
spider after it, up a branch reaching to the ground, until it got 
high enough, when it flew heavily off with it. It was so small, 
and the spider so heavy, that it probably could not have 
raised if from the ground by flight. All over the world there 
1 Natural Selection, by A. R. Wallace, p. 272. 
