86 



THE REPORT OF THE 



119 



Fig. 40. — The four stages in the butterfly's life-history are 

 represented, eggs, larvae or caterpillars, chrysalis and imago. 



The common Cabbage -butterfly is not a 

 native of this Continent, but has been imported from 

 Europe within recent years. It reached Quebec 

 about 1860; -v, 



in 1863 it 

 was quite 

 common 

 about Que- 

 bec; in 1867 

 FlG - 41 - i t w a s i n 



Montreal ; in 1868 it spread from New York 



where it had been introduced from Europe ; by 



1881 it had spread throughout the eastern half of 



Continent ; by 1886 the Rocky Mountains had Fig. 42. 



been reached ; and now it roams from the Atlantic to the Pacific. It displaced the 



native species (Pieris protodice), Figs. 41, male, 42, female, driving it before it; bu 



after thirty-six years of occupation the same native form re-appears with renewed vigor, 



and gives signs of competing successfully with the intruder. 



Lesson I. — The Eggs 



Leaves of cabbage, turnip, or rape with the eggs should be collected. On which side 

 of the leaves are the eggs found? Of what advantage 1 What is the shape of the eggs? 

 The color? "What kind of an insect lays these eggs? What kind of creatures hatch from 

 these eggs? Do they resemble the mother insect? How long before the eggs hatch? 

 (It is important that the pupils should have the eggs under observation. If possible the 

 study should be made on the objects in the fields, under natural conditions, but leaves 

 might be brought into the class room). 



