The Life-History and Anatomy of Butterflies 



milkweed butterfly, Anosia plexippus, which is distasteful to 

 birds, and hence enjoys peculiar freedom from the attacks of 

 enemies. Because this adaptation of one form to another evi- 

 dently serves the purpose of defense this phenomenon has been 

 called " protective mimicry." The reader who is curious to know 

 more about the subject will do well to consult the writings of 

 Mr. Alfred Russel Wallace and Mr. Darwin, who have written at 

 length upon mimicry among butterflies. There is here a field of 

 most interesting inquiry for the student. 



The Distribution of BiitterJties. — ButteriWes are found every- 

 where that plant life suited to the nourishment of the caterpillars 

 is found. There are some species which are arctic and are found 

 in the brief summer of the cold North and upon the lofty summits 

 of high mountains which have an arctic climate. Most of them 

 are, however, children of the sun, and chiefly abound in the tem- 

 perate and tropical regions of the earth. While the number of 

 species which are found in the tropics vastly exceeds the number 

 of species found in the temperate zone, it is apparently true that 

 the number of specimens of certain species is far more numerous 

 in temperate regions than in the tropics. Very rarely in tropical 

 countries are great assemblages of butterflies to be seen, such as 

 may be found in the summer months in the United States, swarm- 

 ing around damp places, or hovering over the fields of blooming 

 clover or weeds. In the whole vast region extending from the 

 Rio Grande of Texas to the arctic circle it is doubtful whether 

 more than seven hundred species of butterflies are found. On 

 the continent of Europe there are only about four hundred and 

 fifty species. The number of species of butterflies and the num- 

 ber of species of birds in the United States are very nearly the 

 same. 



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