THE MEADOW-BROWNS OR SATYRS 215 



characterized, at least so far as our eastern species are 

 concerned, by their slender bodies and rather large wings, 

 toned in various shades of brown, and marked chiefly with 

 conspicuous and characteristic eye-spots. The larger 

 veins of the front wings are swollen at the base. The 

 caterpillars are rather slender and have a curious division 

 of the last body segment into two parts, which gives them 

 an appearance suggestive of the caterpillar of the Em- 

 peror butterflies, although the Meadow-brown cater- 

 pillars do not have, upon the head, the curious antlers 

 borne by the Emperor larvae. 



The Common Wood-nymph or Grayling 



Cercyonis alope 



In the development of our knowledge of both birds and 

 mammals as found upon the American continent the ex- 

 perience in many cases has been essentially this: a bird 

 or a mammal was first described from some well-known 

 region of North America, commonly from specimens car- 

 ried to Europe by early voyagers. Later other species of 

 the same genus were brought to light by various explorers 

 and given specific names. As each section was thus ex- 

 plored a new form differing markedly from the others was 

 found and named. At a later period, when great collec- 

 tions were brought together so that one observer was able 

 to make a careful survey of specimens from all parts of the 

 continent, it was found that many of these species merged 

 into each other through intergrading forms from regions 

 between the locaHties of the original species. So it has 

 come about that in the case of a large number of our birds 



