OF THB \ 



UNIVERSITY) 



IN THE FIELI)V^( 199 



plants are recommended by the United States Department 

 of Agriculture as a good pot herb. 



As the milkweeds are prolific seed-bearers, and also spread 

 and increase by means of rootstoclcs which remain alive from 

 year to year, they appear wdl qualified to compete with other 

 plants, and also to hold their own against man. Of what 

 advantage is the double mode of propagation to a plant? 

 How long would it take a rootstock to creep fifty miles 

 under ground ? Could it cross a river ? Some plants have 

 almost become extinct near our towns and villages. Do 

 you think the milkweeds will soon be amongst them ? 



Insects seen in Fields 



If we found very many birds that are undoubtedly the 

 farmer's friends, we must say that many insects are amongst 

 his worst enemies. We shall now study a few of the com- 

 mon insects which we have observed in fields. We will 

 begin with the prettiest of them, the butterflies. 



30. The White Cabbage Butterflies. 



MATERIAL : Live butterflies on a spray of weeds in a glass jar ; 

 caterpillars at various stages of growth, feeding on cabbage leaves ; 

 pieces of cabbage leaves with butterfly eggs on the lower sides. It 

 is not important that the children should distinguish the native species 

 from the imported, nor the males from the females. The children 

 should have observed the insects in all their stages. 



There are two very common species of cabbage butterflies ; 

 both have white wings marked with black and more or less 

 tinged with yellow. On the first warm days of spring we 

 see them flying about. "They are indeed harbingers of 

 spring, and they delight the eyes of all observers so much 

 more because insects of all kinds have been absent for the 

 last six months. These butterflies, though apparently such 

 frail objects, can stand a great deal of ill treatment at this 



