i.] IMPERFECTION OF FLOWERS. 31 



tilized by night-flying insects, many of the flowers open 

 in the day, and consequently remain sterile. It is 

 of course possible that these cases may be explained 

 away ; nevertheless, as both insects and flowers are con- 

 tinually altering in their structure, and in their geo- 

 graphical distribution, we should naturally expect to 

 find such instances. Water continually tends to find its 

 own level ; animals and plants as constantly tend to adapt 

 themselves to their conditions. For it is obvious that 

 any blossom which differed from the form and size best 

 adapted to secure the due transference of the pollen 

 would be less likely to be fertilized than others ; while 

 on the other hand, those richest in honey, sweetest, and 

 most conspicuous, would most surely attract the atten- 

 tion and secure the visits of insects ; and thus, just as 

 our gardeners, by selecting seed from the most beauti- 

 ful varieties, have done so much to adorn our gar- 

 dens, so have insects, by fertilizing the largest and 

 most brilliant flowers, contributed unconsciously, but 

 not less effectually, to the beauty of our woods and 

 fields. 1 



1 I have treated the subject of this lecture at greater length in a 

 little book on Flowers and Insects, forming one of the "Nature 

 Series." 



