272 SIR JOHN LUBBOCK ON THE 
2. 
He then eut some disks without central holes, and pinned 
them over the flowers so as to hide, without touching, the tubular 
flowers. The visits of insects were about as numerous as before. 
To this experiment, however, the same objections may be made 
as to the first. 
I might also observe that to us Dahlias have no scent, and 
though it is possible that they may nevertheless emit an odour 
attractive to insects, there is no evidence of this. Surely it 
is somewhat illogical to assume that the Bees are guided by 
the sense of smell, when we have no evidence that, as a matter of 
fact, any scent is emitted. 
3. 
In his next series of experiments, Prof. Plateau used leaves 
instead of coloured paper. The results were similar, but the 
experiments are open to the same objections. 
Yet he observes that * Aprés ces expériences, il semble, au 
moins pour les Insectes observés, que ni la forme ni la couleur 
des fleurs ne les attirent ; que c'est surtout et peut-être exclu- 
sivement l'odorat qui les guide." Surely in any case, and even 
apart from the remarks already made, this is not a logical 
sequence. The theory which Prof. Plateau attacks is that 
insects are attracted to flowers by their smell and colour. It 18 
part of the theory that the scent of flowers is important a 
attracting insects. Even if Prof. Plateau had proved, which I 
submit he has not, that in his experiments the insects were 
attracted by smell, and that they did not see the coloured corollas, 
this would not prove that they are not guided by the coloured 
corollas when they can see them. 
4. 
In his next series of experiments Prof. Plateau masked all the 
flowers, and yet insects came. “Dans ces conditions,” he a 
" l'observateur placé devant la rangée de Dahlias ne voit plus 
aucune fleur" No; but let him move round, as Bees would, a 
he would see the backs and sides of the flowers, which would be 
quite sufficient. : 
Moreover, it is evident that on previous days the Dahlias had 
been visited abundantly by insects. These would of ar 
return, and though they might be a little disconcerted by Pret 
Plateau’s disks, the flowers would have to be much better hidden 
if they were to remain undiscovered. 
