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Home Nature-Study Course. 



at the place where the two join. As a matter of fact, the ear of corn is on a 

 branch stalk which has been very much shortened so that the nodes are very close 

 together and, therefore, the leaves come off close together. By stripping the husks 

 back one by one the change from the outside, stiff, green leaf structure to the inner, 

 delicate, papery wrapping for the seed, may be seen in all its stages. This is a 

 beautiful lesson in showing how the maize protects its seed, and may well be com- 

 pared to the clothing of a baby. The pistillate flowers of the corn, which finally 

 develop into the kernels grow in pairs along the end of the shortened stalks which 

 is later the cob. Therefore, the ear will show an even number of rows and the 

 cob shows distinctly that the rows are paired. The corn silk is the stigma of the 

 pistillate flower and, therefore, in order to secure pollen must extend from the 

 ovule, which later develops into a kernel to the tip of the ear where it protrudes 

 from the end of the husks. If the corn silk be examined through a lens early in 

 the season its tips will be seen to be divided into two threads, each covered with 

 short hairs ; these are the stigmas on which the pollen falls ; and the pollen is 

 obliged to grow down through the whole length of the silk to reach the ovule. A 

 computation of the number of kernels in a row and on the ear makes a very good 

 arithmetic lesson for the primary pupils, especially as the kernels occur in pairs. 



LESSON VIII. 

 THE GROWTH OF CORN. 



Purpose. — To give the pupil some points for observing the way that 

 corn grows. 



It is always well when the summer vacation comes to give the pupils 

 some work in observation that may be done out-of-doors during the 

 sur/mer. This lesson might begin with the watching of the germination 

 of the corn while the school is still in session and then be continued in 

 the garden or the field later. 



Observation on the groivtJi of corn: 



1. How does the leaf look when it first comes up? 



2. How many leaves are there in the pointed roll, which first appears 

 above the ground? 



3. How long before the central stalk appears? 



4. When do the tassels first appear ? 



5. When do the tassels shed their pollen? 



6. How large are the ears when the pollen is being shed? 



7. Study the corn silk at this period and see the stigmas. 

 Experiment i on corn growth: Compare the growth of a corn plant 



with that of a pigweed. When the corn stalk first appears tie two strings 

 on the stalk, one just above the joint and one below it. Tie two strings 

 the same distance apart on the stem of a pigweed. Measure carefully 

 the distance between these two strings; two weeks later measure the 

 distance between the strings again. 



Experiment 2. — Measure the distance between two of the nodes 

 toward the tip of a corn stalk; two weeks later measure this distance 

 again. 



