PHYSIOLOGICAL PROCESSES IN PLANTS 65 



b. Seed Testing 1 



1. GERMINATION 



Method. Make a shallow wooden tray about l\ inches deep, 15 inches 

 wide, and 23 inches long. Divide the tray into small spaces about 1 

 inches square by a checkerboard lacing of twine across the top. Fasten 

 the twine by tacks, 

 and number the rows 

 in both directions ori 

 the sides of the tray. 

 There should now be 

 about 10 rows of 

 squares the narrow 

 way and 15 the other, 

 as in Figure 11. Be- 

 fore finally lacing to 

 form the squares, 

 loosely fill the tray 

 with dry sand or saw- FlG 1L _ See( j testing frame. (After Howe.) 

 dust. Soil may be 

 used, although not so clean to handle. 



Arrange ears of seed corn in rows of ten to correspond with the ten 

 rows of squares, or carefully label each ear to correspond with a certain 

 square. Arrange the ears on shelves, where they will not be disturbed 

 until after the test is completed. 



When ready to begin the test, take ear number one, and carefully re- 

 move five kernels from each ear. (The kernels from the tips of each ear 

 should not be used.) Take kernels of average size, removing them in a 

 spiral manner around and lengthwise of the ear, from about one inch of the 

 base of the ear and one inch of its tip. Plant each of these five kernels 

 in the square which corresponds with the ear from which they were taken. 

 Push a kernel in each of the four corners of the square point downward, 

 and the fifth in the middle. Push all to a uniform depth, just far enough 

 to be covered with sand when the forefinger is withdrawn. 



After the planting is completed, lay a small piece of paper flat on the 

 tray and pour water on the paper until the sand is thoroughly saturated. 

 Put the tray in a warm place and keep the sand watered until the young 

 shoots are an inch or so high. 



Observation. Examine the squares in regular order and carefully 

 note the condition of the young seedlings. Tabulate your results, show- 

 ing the number in a square in good condition and the number in poor 

 condition. 



Conclusions. 1. If all five plants of a square are thriving and sturdy, 

 what is your decision concerning the ear from which these seeds came ? 



2. Suppose two or more of them are shorter, or look pale and sickly. 

 What about the chances concerning the ear from which they came ? 



i Adapted from Howe, Circ. 96, U. S. Dept. Agri., 1910. 

 SHARPE'S LAB. MAN. 5 



