198 HANDBOOK OF NATURE STUDY 



flowers constructed on the same plan, by which they can at 

 once be recognized. 



What insects have you found on the flowers of milk- 

 weeds ? How many of you have ever found caterpillars 

 with black and yellow stripes on milkweeds ? They are the 

 larvae of the large and very common Monarch Butterfly. 



The seeds. Find by actual count how many flowers there 

 are on one plant. You will find that only a few of these 

 are fertilized and develop seeds. 



If you are a superficial observer, you will probably say, 

 " Well, now, that intricate contrivance for insect-fertiliza- 

 tion is not very successful after all"! " But if you will now 

 take the trouble and also count the number of seeds in a 

 pod, and remember that from two to six pods are produced 

 on one plant, you will be compelled to admit that insect- 

 fertilization in milkweeds is eminently successful. From 

 four hundred to fifteen hundred seeds seems sufficient for 

 one plant. There are two ovaries in each flower. Why 

 could not every one of them develop into a full-sized seed 

 pod ? Of what possible use can the large number of flowers 

 be to the plant if only a few produce seeds ? Imagine 

 yourself a bee and looking for milkweed honey. 



Dissemination of seeds. It is not enough that a plant 

 should produce seeds ; these seeds must be scattered in some 

 way, for if they all dropped near the parent plant and re- 

 mained there, they would perish for lack of space. Examine 

 a ripe milkweed seed and see if you can tell what happens 

 when the pods burst. Let the children describe the struct- 

 ure and dissemination of these seeds. Why could they not 

 be heavy like nuts and acorns ? How are heavy seeds dis- 

 seminated ? 



The common milkweed is sometimes troublesome in 

 fields. If you know the life history of the plant, you 

 should be able to suggest a remedy. Young milkweed 



