1 902-1903.] Ants in Relation to Flowers. 17 



for the time being, of maintaining its own species. So if self- 

 fertilisation is less beneficial to the plant than cross-fertilisa- 

 tion, it is obvious that in the long-run the plant that can bring 

 about cross-fertilisation will have the advantage over one that 

 cannot do so. In all these processes time is one of the great 

 factors concerned — time, that is, rather in the geological sense 

 than in the sense in which the word is ordinarily used. And 

 just as in the case of animals, a given habit or tendency is 

 likely to be transmitted, and as beneficial modifications tend 

 to prolong the life of the species, so we may justifiably refer to 

 these responses on the part of both animals and plants to ex- 

 ternal stimuli as if they were due to actual volition on the 

 part of the individuals, instead of being, as they really are, the 

 outcome of a long series of slight modifications which have 

 proved beneficial to the organism as a species and not to it as 

 an individual. I shall therefore adopt that tone in the re- 

 maining remarks, and shall refer to changes in plant morph- 

 ology as if they had arisen at the will of the individual. 



Assuming that it has been clearly proved that it benefits 

 plants to have pollen brought to them from other individuals 

 of the same species, we may go on to consider some of the 

 devices which plants have employed as means of bringing 

 about this desirable end. In the first place, they have to find 

 out suitable agents for the purpose, and to select out of many 

 the best for the purpose. The action of the wind answers 

 well enough for some. Other agents fulfil the requirements 

 of another set. But a large number of plants have found out 

 that large flying insects, such as certain Lepidoptera and most 

 Bees, give results which are most satisfactory of all. That 

 being the case, the question arises. How best to attract them so 

 that they may come and do the work ? How we should set 

 about work of a similar kind is plain enough if we only con- 

 sider how, say, money is raised for some charitable purpose. 

 We get up a bazaar, and we stock it with a number of trifles, 

 including confectionery, and get some attractive ladies to agree 

 to take stalls. Then we hang out a great number of brightly 

 coloured flags which can be seen a long way off, and we put 

 up notices at the entrance showing the desirable visitor which 

 way to go ; and there are endless devices to attract people to 

 come, and to make their ingress as pleasant as possible. So 



VOL. V. B 



