CHAPTER IV.— Concluded. 



Mono, Di, Polyeot> ledonus Plants — 



How many cotyledons has a bean? How 

 many cotyledons has corn? All plants 

 such as corn are monocotyledons, plants 

 with one cotyledon. All plants such as 

 bean dicotyledons, having two. Some 

 seeds, such as pine tree seeds, have 

 many cotyledons and are called poly- 



— Fourth Exercise. 1 1 



cotyledons. All plants belong to one 

 of these classes. 



Distance Apart for Plants — Examine 

 the wheat and the corn roots (exercise 

 5). The roots of the wheat run 

 side by side and are very long. They 

 are deep roots. Plants having such 

 roots may grow close to each other 

 without crowding. The corn roots are 

 not so long, and near the stem many 

 surface and bracing roots are forming. 

 Plants with branching surface roots 

 must be planted far apart. 



Many seeds do not germinate. At 

 first sowing put many seeds in the 

 trench and later thin out the weak 

 plants. Plants such as lettuce, which 

 mature above ground, should be thinned 

 until they are as far apart as the dis- 

 tance across a mature plant. Chapters 

 9 and 10 tell you more about sowing 

 seeds and thinning plants. • 



By this time you should know why a 

 good seed bed is necessary. You should 

 know considerable about preparing 

 such a bed and you should know how 

 deep to plant seeds. If you are not to 

 have a school garden, ask your parents 

 for a plat at home, or start a garden in 

 a window box. The following chapters 

 will tell you many interesting things 

 about gardening. 



QUESTIONS 



1— What starts germination in a 

 seed? 



2 — Of what use is the micropyle? 



3 — What effect has sugar in the seed? 



4 — Where does it come from? 



5— Why should seeds be buried in the 

 soil? 



—Fifth Exercise. 



6 — What is a seed? 



7 — How do we know how deep to 

 plant seeds? 



8 — How are plants grouped? 



9 — How do we know now far apart 

 to grow plants? 



Home Studies 



1 — Examine the seeds of many differ- 

 ent plants. .What about the seed helps 

 to bury them? 



2 — Dig up corn and wheat plants, 

 wash off the dirt and compare the 

 roots. 



3 — Open several pea and bean pods. 

 Are the seeds in the separate pods all 

 the same size? 



4 — Germinate as many seeds as you 

 can find from weeds to the cocoanut. 

 Note the embryo, and food supply of 

 each. 



5 — -Note the great number of seeds 

 produced by one plant. Why is this? 



6 — If you live on or near a farm ex- 

 amine a handful of seed that is to be 

 sown. Can you .find any foreign seeds? 



7 — Make a list of seeds that are blown 

 about, that are carried by water, that 

 are distributed by animals. 



8 — Visit a nursery and see where 

 flower seeds come from. 



— Sixth Exercise. 



Communications should be sent to 



C. A. STEBBINS, Editor 



Agricultural Education Division 



