REVIEW. 277 
already mentioned, effected principally either by the wind or by insects, 
though in some cases it is due to other agencies, as, for instance, by birds, 
or by water. For instance, in the curious Vallisneria spiralis the female 
flowers are situated on long stalks which are spirally twisted, and grow very 
rapidly, so that even if the level of the water alters, provided this be within 
certain limits, the flowers float on the surface. ‘The male flowers on the 
contrary are minute and sessile, but when mature they detach themselves 
from the plant, rise to the surface and float about freely like little boats 
among the female flowers. Wind-fertilised flowers as a rule have no 
colour, emit no scent, produce no honey, and are regular in form. Colour, 
scent, and honey are the three characteristics by which insects are attracted 
to flowers.” 
Speaking of the white dead-nettle (Zamiwm album), at 
page 17: — 
“In the first place, the honey attracts insects. If there were no honey, 
they would have no object in visiting the flower. The bright colour is 
useful in rendering the flower conspicuous. The platform serves as an 
alighting stage for bees. 'The length of the tube has reference to that of 
their proboscis, and prevents the smaller species from obtaining access to 
the honey, which would be injurious to the flower, as it would 
remove the source of attraction for the bees, without effecting the 
object in view. The upper arch of the flower protects the stamens 
and pistil, and also presses them firmly against the back of the 
bee. So that, when the bee alights on the stage and pushes its proboscis 
down to the honey, its back comes into contact with them. The row of small 
hairs at the bottom of the tube prevents small insects from creeping down 
the tube and stealing the honey. Lastly, the small processes on each side 
of the lower lip are the rudimentary representatives of parts, formerly more 
largely developed, but which, having become useless, have almost 
disappeared.” 
Concluding the first lecture, Sir John says :— 
“For it is obvious that any blossom which differed from the form and 
size best adapted to secure the due transference of the pollen would be less 
likely to be fertilised than others; while on the other hand, those richest 
in honey, sweetest, and most conspicuous, would most surely attract the 
attention and secure the visits of insects; and thus, just as our gardeners, 
by selecting seed from the most beautiful varieties, have done so much to 
adorn our gardens, so have insects, by fertilising the largest and most 
brilliant flowers, contributed unconsciously, but not less effectually, to the 
beauty of our woods and fields.” 
Lecture No. 2 is of great imterest to the lepidopterist, for 
amongst other subjects the author seeks the show the use of the 
