476 Creation by Law. [Oct., 



The latter would be well fertilized, and the longest would on the 

 average be the best fertilized of all. By this process alone the 

 average length of the nectary would annually increase, because, the 

 short ones being sterile and the long ones having abundant offspring, 

 exactly the same effect would be produced as if a gardener destroyed 

 the short ones and sowed the seed of the long ones only ; and this 

 we know by experience would produce a regular increase of length, 

 since it is this very process which has increased the size and 

 changed the forra of our cultivated fruits and flowers. 



But this would lead in time to such an increased lenoth of the 



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nectary that many of the moths could only just reach the surface of 

 the nectar, and only the few with exceptionally long trunks be able 

 to suck up a considerable portion. 



This would cause many moths to neglect these flowers because 

 they could not get a satisfying supply of nectar, and if these were 

 the only moths in the country the flowers would undoubtedly suffer 

 and the further growth of the nectary be checked by exactly the 

 same process which had led to its increase.. But there are an 

 immense variety of moths of various lengths of proboscis, and as 

 the nectary became longer other and larger species would become 

 the fertilizers, and would carry on the process till the largest moths 

 became the sole agents. Now, if not before, the moth would also 

 be affected, for those with the longest probosces would get most 

 food, would be the strongest and most vigorous, would visit and 

 fertilize the greatest number of flowers, and would leave the 

 largest number of descendants. The flowers most comjDletely 

 fertilized by these moths being those which had the longest 

 nectaries, there would in each generation be on the average an 

 increase in the length of the nectaries, and also an average increase 

 in the length of the proboscis of the moths, and this would be a 

 necessary result from the fact that nature ever fluctuates about 

 a mean, or that in every generation there would be flowers with 

 longer and shorter nectaries, and moths with longer and shorter 

 probosces than the average. No doubt ' there are a hundred causes 

 that might have checked this process before it had reached the 

 point of development at which we find it. If, for instance, the 

 variation in the quantity of nectar had been at any stage greater 

 than the variation in the length of the nectary, then smaller moths 

 could have reached it and have effected the fertilization. Or if the 

 growth of the probosces of the moths had from other causes 

 increased quicker than that of the nectary, or if the increased 

 length of proboscis had been injurious to them in any way, or if 

 the species of moth with the longest proboscis had become much 

 diminished by some enemy or other unfavourable conditions, then 

 in any of these cases the shorter nectaried flowers which would have 

 attracted and could have been fertilized by the smaller kinds of 



