1867.] Creation by Law. 475 



tion is this. The pollen of this flower can only be removed by the 

 proboscis of some very large moths trying to get at the nectar at 

 the bottom of the vessel. The moths with the longest proboscis 

 would do this most effectually ; they would be rewarded for their 

 long noses by getting the most nectar ; whilst on the other hand, 

 the flowers with the deepest nectaries would be the best fertilized 

 by the largest moths preferring them. Consequently, the deepest 

 nectaried Orchids and the longest nosed moths would each confer 

 on the other a great advantage in the 'battle of life.' This would 

 tend to their respective perpetuation and to the constant lengthen- 

 ing of nectar and noses." The Duke of Argyll then quotes Darwin's 

 diffident statement " that we can thus partially understand how 

 this astonishing nectary was produced," and says it is indeed but a 

 partial understanding, — but he does not show what point the 

 explanation given fails to meet. I maintain, on the contrary, that 

 the laws of multiplication, variation, and survival of the fittest, 

 already referred to, would under certain conditions necessarily lead 

 to the production of this extraordinary nectary. Let it be remem- 

 bered that what we have to account for is only the unusual length 

 of this organ. A nectary is found in many orders of plants and is 

 especially common in the Orchids, but in this one case only is it 

 more than a foot long. How did this arise ? We begin with the 

 fact, proved experimentally by Mr. Darwin, that moths do visit 

 Orchids, do thrust their spiral trunks into the nectaries, and do 

 fertilize them by carrying the pollinia of one flower to the stigma 

 of another. He has further explained the exact mechanism by 

 which this is effected, and t\\Q Duke of Argyll admits the accuracy 

 of his observations. In our British species, such as Orchis pyrami- 

 dalis, it is not necessary that there should be any exact adjustment 

 between the length of the nectary and that of the proboscis of the 

 insect, and thus a number of insects of various sizes are found to 

 carry away the pollinia and aid in the fertilization. In the 

 Angrsecum sesquipedale, however, it is necessary that the proboscis 

 should be forced down into a particular part of the flower, and this 

 would only be done by a large moth straining to drain the nectar 

 from the bottom of the long tube.* Now let us start from the time 

 when the nectary was only half its present length or about six 

 inches, and was chiefly fertilized by a species of moth which 

 appeared at the time of the plant's flowering, and whose proboscis 

 was of the same length. Among the millions of flowers of the 

 Angraecum produced every year some would always be shorter than 

 the average, some longer. The former, owing to the structure of 

 the flower, would not get fertilized, because the moths could get all 

 the nectar without forcing their trunks down to the very base. 



* It is a peculiarity of this species that the nectar only occupies a depth of one 

 ur two inches at the bottom of the nectary. 



