104 INSECTS. 



The large, red-brown milkweed butterfly, with dark 

 markings along the veins, is of the family Nymplialidce. 

 Compare it with a representative of each of the two other 

 families mentioned. 



Notice that all the names of families end in -idee. 



The Order. Note that the smallest group among ani- 

 mals is the species, and comprises those animals which are 

 essentially alike. Note that as species are put together to 

 form a genus, so genera are put together to form a family. 

 Families, in like manner, make up an order. The three 

 families mentioned, together with several other families 

 of butterflies and moths, comprise the order Lepidoptera 

 (or scale-winged insects). The names of orders usually 

 end in a. 



This grouping of animals is called classification. 



Note that all groups are founded upon certain likenesses 

 in structure and development. A system of classification, 

 therefore, expresses the structural and developmental rela- 

 tionships which exist between animals. 



Seven of the orders of insects have been studied in a 

 few of their representatives. Write the names of these 

 orders in a column, and opposite each write the characters 

 peculiar to that order. Your list should approximately 

 define these orders. 



Then make a list of the characters which all these have 

 in common. 1 Your list should characterize approximately 

 the group Hexapoda (or insects proper). 



1 If there be time enough, each student so disposed should select, with 

 the advice of the instructor, some small group of insects for a little special 

 study, some genus which offers a number of local species, and one the 

 metamorphoses of which can be followed through in reasonably short 

 time, and one for which systematic works that will enable him to identify 

 the species are at hand. If undertaken at all, the group should be studied 

 as thoroughly as possible, especially as to its metamorphosis, and its 

 place in the economy of nature and of man. Full notes should be made 

 of the things observed during this study; and at its close an account 



