18 THE BUTTERFLIES OF THE WEST COAST 



of butterflies, although their larval food-plant, grasses, is wide 

 spread. 



Further, the food-plant limit is not the only limit ; there is a subtler 

 limit than that, as intimated in Sections 2 and 3, and 39; but the 

 butterflies have not yet told me what the secret is, and I do not 

 know, nor does any other man ; but the butterflies will not fly 

 beyond their natural limit, even where the ordinary food-plant is 

 present, and, further, when the climate apparently offers no hin- 

 drance. On this point I will offer but one example. — the Meli- 

 Iceas, voracious feeders, all of them, which suck the nectar from 

 many flowers, and the larvae of which feed on many scrcphulari- 

 ous plants, chiefly the pentstemons, and which plants grow all 

 over the Coast States from north to south, the southern Meli- 

 tceas do not go far north, nor do the northern Melitceas come far 

 south, although to our grosser senses any limiting causes are not 

 apparent, either in altitude, temperature, or larval food-plants. 



§ 6. Metropolis. 



In a country like the States of the West Coast, — a land of hills 

 and valleys and mountains, — butterflies generally inhabit in the 

 greatest numbers, first, localities where some favorite flower 

 grows, upon the nectar of which flowers both sexes feed ; sec- 

 ond, the females are found where the proper larval food-plant 

 grows, upon which the eggs are placed as they mature ; third, the 

 males can always be found on the bare, open hilltops, where they 

 idly disport themselves, taking a pugnacious delight in worrying 

 and driving off other butterflies, or in playing with those kinds 

 with which they are at peace. 



But, sometimes you will run upon a metropolis unexpectedly, 

 and in the oddest places, and if you are hunting in a strange 

 country you will in a moment, and unexpectedly, find yourself 

 face to face with a metropolis, and wrestling with a flying host 

 of the beauties which you have come so far to see. On this point 

 I could relate some interesting stories, but this is not a story book, 

 so I refrain. 



§ 7. Types. 



A "Type" is the specimen or specimens upon which the written 

 description, constituting the "publication" of a species, is founded, 

 and which carefully describes that type specimen. A species 

 should be founded upon one male and one female specimen, of 



