1596 THE BUTTERFLIES OF NEW ENGLAND. 



upon the very plant upon whicli the caterpillar will feed. In certain 

 instances where the plants are abundant, as in the ease of" grasses, the 

 butterfly may lay upon an object in the near vicinity and this, too, has 

 happened in a few instances in the case of butterflies which are more 

 particular in their choice. Thus, I once saw a European Satyrid 

 lay an egg on a dead blade of grass lying loose upon the ground, have 

 seen one of our species of Brenthis lay eggs upon grass in the vicinity of 

 nolet, and found the egg of a Pamphilid upon a thistle growing among 

 grasses. These exceptions seem only to prove the general rule that the 

 eggs of butterflies are laid directly upon the food plant of the young. 



This is an act of instinct, one will say. But is this any explanation? 

 We wish to know how the instinct acts. A parent butterfly that in its 

 early life has been nourished upon willow, has no means in the winged 

 condition of tasting the willow to recognize it. Werneburg, indeed, tries 

 to argue that butterflies have no sense of taste because they often seek 

 water, adding that meteoric water has no taste ; but the water drunk by 

 them is extracted from and lies upon the soil from which it will have 

 gained some taste, and he strangely overlooks the fondness of many 

 for ammoniacal waters and of all for the honeyed sweets of flowers. There 

 can be no doubt indeed of their powers of taste, but it cannot be by this 

 means that they recognize the plants upon which their young should feed, 

 their organs of obtaining food being suited only for liquid nourishment. 



Nor can it be by sight. It is true that butterflies are attracted by 

 flowers through their means of vision. Interesting stories are told of their 

 being deceived by painted or artificial flowers. But in these cases there is no 

 reason to suppose that it is anything but the tint in mass that attracts them 

 to the coveted spot. Pray how does the green of one plant diflfer from all 

 others ? Anatomy and experiment both teach us in the clearest way that 

 buttei-flies have no power of vision sufficient for any such powers of dis- 

 tinction as are required of them in selecting special food plants for their 

 young ; which yet they discover in an unei'ring manner. 



There remains apparently nothing but smell. That their sense of smell 

 is acute is plain from facts coming from a quite different source, which 

 have been collected in a previous excursus on Aromatic Butterflies. The 

 production of odor implies the recognition of odor, and inasmuch as the 

 organs through which the odor is known in many cases to be emitted exist 

 in a very much larger number of butterflies than have been recognized as 

 odorous, it would seem a warrantable conclusion that, though we 

 cannot perceive their odor, they nevertheless produce odors recognizable 

 by their mates. Now, we know in a similar way that many plants are 

 odorous quite apart from their flowers ; and if one, with this idea in 

 mind, will but watch the movements of a mother butterfly seeking a spot 

 whereon to lay her eggs, he will not fail to recognize that many of these 



