32 ELEMENTS OF AGRICULTURE 



3. There are about 225,000 alfalfa seeds in a pound. About fifteen 

 to thirty pounds is sown per acre. If twenty pounds is sown, how many 

 seeds would there be on a square foot? Some good old fields do not 

 have over five plants per square foot. Why is so much seed sown? If 

 fields are available, count the number of plants on old and new seed- 

 ings. Do the same principles apply in planting corn? To what other 

 plants do they apply? 



4. Why are the ears on a cornstalk not always filled out? 



5. What part of the flower are the corn silks? Where are the other 

 parts? To what are the silks attached? 



6. What effect does wet weather at blossoming time have on an 

 apple crop? What effect does dry weather at silking time have on the 

 corn ears? Why is a frost at blossoming time more injurious to peaches 

 than one later? 



7. What would be the proportion of red and white peas at the end 

 of the fifth generation from the hybrid between them? 



8. Why is the ratio in which hybrids break up not exactly 3 to 1 

 when dealing with small numbers? 



9. Why do apples, peaches and potatoes not come true from the seed? 



10. Are small potatoes as good as large ones for planting? 



11. Are the kernels of corn from the tip and butt good for planting? 



12. What crops, or new varieties of crops, if any, have been re- 

 cently introduced into your region? 



13. What seeds of farm crops are regularly shipped into your 

 county? Where do they come from? Is the climate of the region from 

 which they came similar to yours? 



LABORATORY EXERCISES 

 1. Variation in Plants. 



Materials. A number of elm leaves for each student, or leaves of 

 some other plant, two corn-stalks or other plants for each student. 



Try to find two leaves that are alike. 



Make a list of all the leaf characters, and tell how the leaves differ 

 in each character. 



Make a list of all the characters of the two corn plants and state 

 the differences: Number of leaves, height and diameter of stalk, number 

 of parts in the tassel, number of ears, size and shape of leaves, number 

 of ribs, length and diameter of ear, number of rows of kernels, color 

 of kernels, color of cob, shape of kernels, size of embryo and endo- 



