NATURAL SELECTION 141 



certain; for I have repeatedly seen, but only in the au- 

 tumn, many hive-bees suclcing the flowers through holes 

 bitten in the base of the tube by humble-bees. The dif- 

 ference in the length of the corolla in the two kinds of 

 clover, which determines the visits of the hive-bee, must 

 be very trifling; for I have been assured that when red 

 clover has been mown, the flowers of the second crop are 

 somewhat smaller, and that these are visited by many 

 hive-bees. I do not know whether this statement is ac- 

 curate; nor whether another published statement can be 

 trusted, namely, that the Ligurian bee, which is gen- 

 erally considered a mere variety of the common hive-bee, 

 and which freely crosses with it, is able to reach and 

 suck the nectar of the red clover. Thus, in a country 

 where this kind of clover abounded, it might be a great 

 advantage to the hive-bee to have a slightly longer or 

 differently constructed proboscis. On the other hand, as 

 the fertility of this clover absolutely .depends on bees 

 visiting the flowers, if humble-bees were to become rare 

 in any country, it might be a great advantage to the 

 plant to have a shorter or more deeply divided corolla, 

 ISO that the hive-bees should be enabled to suck its flow- 

 lers. Thus 1 can understand how a flower and a bee 

 might slowly become, either simultaneously or one after 

 the other, modified and adapted to each other in the most 

 perfect manner, by the continued preservation of all the 

 individuals which presented slight deviations of structure 

 mutually favorable to each other. 



I I am well aware that this doctrine of natural selection, 

 jxemplified in the above imaginary instances, is open to 

 ;he same objections which were first urged against Sir 

 harles Lyell's noble views on "the modern changes of 



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