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D.—ZOOLOGY. 79 
and accumulation of these small variations as the result of environmental 
conditions.’ Except for the implied restriction of selection to * almost 
imperceptibly small variations,’ the statement appears to express fairly the 
opinion of many believers in Natural Selection at the centenary of the British 
Association. One main criticism of this belief was that it led to ‘the 
facile teleology, which, like a noxious weed, had overgrown the solid 
framework of evolutionary doctrine.’ But this was not a necessary nor, 
in my opinion, a common result of the evolutionary beliefs of those 
years. Let me give two examples of teleological interpretations offered 
forty years ago, interpretations which are anything but ‘ noxious 
weeds, being extremely interesting in themselves and pointing directly 
to further researches and a further strengthening of the ‘solid frame- 
work.’ 
On his return from a visit to Ceylon and Southern India in 1889 and 
1890 Sir John Farmer gave at Oxford a most interesting lecture on his 
experiences. I recall two of his observations which have always seemed 
to me most illuminating. One concerned a Loranthus, which is so 
successful that it threatens the very existence of certain introduced trees. 
It possesses a viscid fruit which adheres to stem and leaves; then from 
the seed the embryo puts out a sucker borne at the end of a rather thick 
stalk which curls down and fixes itself to anything it touches. The stalk 
then straightens and the fruit, containing the germinating seed, is borne 
aloft. If, however, as he believed, the sucker becomes attached to an 
unsuitable surface, the stall bends over again and makes another attempt 
_ to reach a living structure which can be penetrated ; and if this fails the 
process continues, causing the fruit to travel in search of favourable 
opportunities, naturally denied to those which he often saw thickly 
covering the telegraph wires in the Nilgiri Hills. 
The second observation was made upon flowering plants which depend 
for cross-fertilisation on insect-visitors and the honey which attracts 
them. Such flowers are well known to be robbed by insects which bite 
their way in and steal the honey without doing their work. Now Sir 
John Farmer observed that in certain species this difficulty was met by 
the development, on the outside of the flower, of special glands attractive 
- to a bodyguard of ants so that the lazy visitors would be compelled to 
seek the proper entrance and the thieves driven away. This observation 
has always seemed to me especially significant, as showing how the simple 
operation of Natural Selection may simulate a rather elaborate process of 
reasoning. We may wonder whether it would have satisfied the zoologist 
of whom Darwin wrote to Lyell: ‘Dr. Gray of the British Museum 
remarked to me that “ selection was obviously impossible with plants ! 
No one could tell him how it could be possible!” And he may now add 
that the author did not attempt it to him!’ 
But if either or both of these interpretations should be disproved, if 
the ants in these and other analogous associations should be shown, as some 
believe, to be parasites doing no useful work for the plant—what then ? 
Well, once again hypothesis will have played a fruitful part in stimulating 
and guiding research. 
18 My friend has kindly refreshed my memory on some of the details. 
