97 
— that is to say, from the fact that the pollen of one individual generally 
fertilised the stigma of another ? The following out of this principle led to 
so fertile a field of observation that it absolutely metamorphosed that par- 
ticular branch of botany. All at once it was seen to afford an explanation 
of hundreds of forms of flowers which used to be called irregular, but 
which were really insect-adapted. If this paper had been read in the 
summer-time I could have brought you a garden Nasturtium ( Tropceolum 
majus ) in which I could have shown you a beautiful instance of the 
adaptation of flowers to insect visits. When you look at that flower you 
cannot fail to see that its whole object is to make the most of the spur which 
contains the nectar sought for by the insects. Everything groups itself 
around that spur. First of all there are the five petals, of which the two 
upper and more prominent ones are the more richly coloured, their darker 
streaks pointing the way the butterfly has to go. The three lower petals 
have fringes so placed as to prevent the ants going past them to steal 
the nectar. Being so brilliantly coloured the flower is not adapted to 
moths, because they only fly by night and generally make for the white 
flowers ; and whatever butterfly comes, the proboscis must be long 
enough to get to the bottom of the tube. The insect alights on the 
three lower petals or on the central part of the flower and inserts its 
proboscis, and in doing so rubs against some of the stamens, of which 
there are eight, which are arranged in a beautiful manner with reference 
to the tube. They are placed in pairs, there being one pair close to 
the opening of the spur, another a little further down, and then another, 
and another, all of them at first, declining or stooping down. Moreover, 
they do not all reach maturity at the same time, but rise up in turns 
one by one, those nearer to the mouth of the tube coming sooner, and 
then the rest in rotation. Whilst this pollen is being shed the device 
adopted to prevent its dusting the stigma of the flowers is that the stigma 
of the individual flower is not yet receptive. The three styles are closely 
applied to each other, and they do not open until all the stamens have 
shed their pollen. These anthers are attached to their filaments by a 
very small pedestal, and then when they have all been emptied, the three 
styles open and are capable of receiving the pollen of another plant. The same 
process takes place in many other flowers, and all I have to say here is 
that we owe all this knowledge to Darwin, who first began to observe what 
was going on in the orchids. Darwin was more familiar with cultivated 
plants than with the wild ones, and his examples were taken mainly from 
what he observed in hot-houses. Had he taken the wild flowers he would 
have found that the cross-fertilisation in their case was quite as wonderful 
as he found it to be among the orchids. I would only mention one — the 
Iris, as to which any one here will be able to make observations for himself. 
I have only now to thank the other speakers for their agreement with me, 
and also this Institute for having given me the opportunity of reading a 
paper which expresses my own opinions, whether they be right or wrong. 
The meeting was then adjourned. 
